Boston University
OpenBU
http://open.bu.edu
Theses & Dissertations
Boston University Theses & Dissertations
2016
Impact of precipitating events on
pediatric chronic pain recovery
Becker, Andrew John
http://hdl.handle.net/2144/16808
Boston University
BOSTON UNIVERSITY
SCHOOL OF MEDICINE
Thesis
IMPACT OF PRECIPITATING EVENTS ON PEDIATRIC CHRONIC PAIN
RECOVERY
by
ANDREW JOHN BECKER
B.S., Boston College, 2014
Submitted in partial fulfillment of the
requirements for the degree of
Master of Science
2016
© 2016 by
ANDREW JOHN BECKER
All rights reserved
Approved by
First Reader
__________________________________________________
Karen Symes, Ph.D.
Associate Professor of Biochemistry
Second Reader
__________________________________________________
Laura Simons, Ph.D.
Associate Professor of Psychology, Harvard Medical School
Staff Psychologist, Boston Children’s Hospital
ACKNOWLEDGEMENTS
I would like to dedicate this thesis first to my PI, Dr. Laura Simons. Without your help
through every step in this process, none of this would have been possible. Also a special
thanks to Dr. Gwynneth Offner and Dr. Karen Symes, for all of their advice that helped
me at BU over the past two years. A big thank you to my parents for supporting me in
everything I do, as well as to Kristen, for being by my side and believing in me
throughout this journey. And finally, to all my friends, especially those in the greatest
group chat of all time, for always pushing me to be a better version of myself.
iv
IMPACT OF PRECIPITATING EVENTS ON PEDIATRIC CHRONIC PAIN
RECOVERY
ANDREW JOHN BECKER
Title: Impact of precipitating events on pediatric chronic pain recovery
Objectives: 1) To measure the prevalence of precipitating events in pediatric chronic pain
patients and 2) to compare pain and functional disability outcomes at evaluation and 4month follow-up by presence and type of precipitating event.
Methods: Precipitating events (e.g., injury) were coded from the medical record for 401
youth (6-19) who presented to a tertiary care chronic pain clinic. Four-month follow-up
disability and pain were collected for 187 patients. In addition to frequency of events, we
examined differences in pain and disability measures by event type at evaluation and
follow-up using multiple statistical analysis strategies.
Results: Two-thirds of patients had a precipitating event prior to pain onset. Injury was
the most common (55%), followed by chronic disease (23%), infection/illness (12.8%),
and surgery (7.5%). Patients whose pain was triggered by injury reported the highest
average pain levels, F(3, 340)=2.67, p<.05 and functional disability, F(3, 295)=3.54,
p<.05. There were multiple cases of event groups that had significantly different baseline
and follow-up psychological measures when compared to the rest of the patient
population. Trajectories of pain and disability did not differ between patients with and
v
without a precipitating event. Patients with injuries reported greater improvement in
functional disability at follow-up (time x injury) F(1, 183)=4.88, p<.05 whereas patients
with chronic disease reported less improvement in disability (time x chronic disease),
F(1, 183)=5.49, p<.05. No other interactions were significant for disability or pain.
Conclusions: A majority of patients had experienced some form of precipitating event
prior to their pain onset, and the presence of a precipitating event had varied effects on
the treatment outcomes of patients at four-month follow-up. Although patients with
injuries presented with greater disability and pain, they had significantly more
improvement, while chronic disease patients were less likely to improve in terms of
functional disability. Type of precipitating event appears to be associated with treatment
response and can inform clinical prognoses.
vi
TABLE OF CONTENTS
TITLE ...................................................................................................................................i
COPYRIGHT PAGE .......................................................................................................... ii
READER APPROVAL PAGE.......................................................................................... iii
ACKNOWLEDGEMENTS................................................................................................iv
ABSTRACT ........................................................................................................................ v
TABLE OF CONTENTS ................................................................................................. vii
LIST OF TABLES..............................................................................................................ix
LIST OF FIGURES ............................................................................................................. x
LIST OF ABBREVIATIONS ............................................................................................xi
INTRODUCTION ............................................................................................................... 1
Pediatric Chronic Pain .................................................................................................................. 1
Underlying Causes of Chronic Pain ............................................................................................. 2
Spontaneous Onset of Chronic Pain ............................................................................................. 6
Aims and Hypotheses ................................................................................................................... 7
METHODS ........................................................................................................................ 10
Participants ................................................................................................................................. 10
Measures..................................................................................................................................... 10
Statistical Analyses .................................................................................................................... 13
RESULTS .......................................................................................................................... 15
vii
Participants ................................................................................................................................. 15
Incidence of Precipitating Events ............................................................................................... 17
Differences in Functioning Across Participating Events: Baseline ........................................... 19
Differences in Functioning Across Participating Events: 4-Month Follow-Up ......................... 26
Examining Trajectories of Pain and Disability .......................................................................... 33
DISCUSSION.................................................................................................................... 36
Aim I: Measuring the Prevalence of Precipitating Events ......................................................... 36
Aim II: Comparing Outcomes at Baseline and Follow-Up ........................................................ 38
Implications ................................................................................................................................ 43
Limitations and Future Direction ............................................................................................... 44
Conclusion .................................................................................................................................. 45
LIST OF JOURNAL ABBREVIATIONS ........................................................................ 46
REFERENCES .................................................................................................................. 47
CURRICULUM VITAE.................................................................................................... 50
viii
LIST OF TABLES
Table
Title
Page
1
Groupings of Pain Diagnoses
16
2
Breakdown of Event Type by Subsequent Pain Diagnosis
18
3
One-Way ANOVAs at Baseline
20
4
Baseline Precipitating Event T-test
22
5
Baseline Injury Event T-test
23
6
Baseline Infection Event T-test
24
7
Baseline Chronic Disease Event T-test
25
8
One-Way ANOVAs at Follow-Up
27
9
Follow-Up Precipitating Event T-test
29
10
Follow-Up Injury Event T-test
30
11
Follow-Up Infection Event T-test
31
12
Follow-Up Chronic Disease Event T-test
32
ix
LIST OF FIGURES
Figure
Title
Page
1
Trajectory of Functional Disability Change in Injury and
Non-Injury Patients
34
2
Trajectory of Functional Disability Change in Chronic
Disease and Non-Chronic Disease Patient
35
x
LIST OF ABBREVIATIONS
ANOVA...............................................................................................Analysis of Variance
CDC............................................................................................Center for Disease Control
CDI....................................................................................Children’s Depression Inventory
CRPS................................................................................Chronic Regional Pain Syndrome
CSI..................................................................................Children’s Somatization Inventory
EDS...............................................................................................Ehler’s Danlos Syndrome
FAP............................................................................................Functional Abdominal Pain
FDI.......................................................................................Functional Disability Inventory
FOPQ-C..................................................................Fear of Pain Questionnaire for Children
IBD..........................................................................................Inflammatory Bowel Disease
IBS................................................................................................Irritable Bowel Syndrome
PCS-C.....................................................................Pain Catastrophizing Scale for Children
PedsQL...........................................................................Pediatric Quality of Life Inventory
POTS................................................................Postural Orthostatic Tachycardia Syndrome
PTSD ................................................................................Post Traumatic Stress Syndrome
RCMAS............................................................Revised Children’s Manifest Anxiety Scale
RSD......................................................................................Reflex Sympathetic Dystrophy
xi
INTRODUCTION
Chronic pain is a major problem that affects countless people across the world. In
a random large sampling of the UK population, close to 50% of people reported the
presence of a chronic pain condition (Elliott, Smith, Penny, Smith, & Chambers, 1999).
This group of people reported multiple different conditions ranging from arthritis, to back
pain, to fibromyalgia. Almost half of these patients reported as having “severe grade”
chronic pain, and just over a quarter expressed having a “highest need” for treatment
(Elliott et al., 1999). A recent systematic review estimated that rates of chronic
widespread pain in the United States are as high as 24%, with most studies reporting that
between 10-15% of Americans experience widespread pain symptoms at any given time
(Mansfield, Sim, Jordan, & Jordan, 2016).
Pediatric Chronic Pain
Chronic pain in pediatrics is arguably an even more significant health problem
within out society because of the negative effects that it has on child development. Many
children who experience chronic pain are severely impaired in their day-to-day lives, and
as a result suffer in both academic and social situations (Hechler et al., 2015). Children
with chronic pain often require multidisciplinary treatment interventions to alleviate their
pain symptoms. Median estimates of the prevalence of chronic pain in childhood range
from 11-38% (King et al., 2011). Moreover, hospital admissions for children with chronic
pain are rapidly on the rise. Inpatient data taken from these admissions shows that the
mean age of patients around thirteen and half years old, and female patients
1
outnumbering male patients at just a little over two to one (Coffelt, Bauer, & Carroll,
2013). The average child that is admitted to a hospital due to chronic pain usually
presents with a variety of comorbid conditions, making treatment decisions complex and
difficult. In a five year, retrospective study on thousands of pediatric pain patients, it was
found that common conditions like tension-type headaches, migraines, and functional
abdominal pain have a high rate of co-morbidity with other pain conditions such as
musculoskeletal pain (Zernikow et al., 2012). The therapeutic challenges that these types
of chronic pain patients present lead to great economic burdens on the families of the
patients, as well as the healthcare systems that are in place to take care of them. Total
annual costs for patients diagnosed with moderate to severe chronic pain conditions were
estimated to be approximately $19.5 billion in the United States alone in 2010
(Groenewald, Essner, Wright, Fesinmeyer, & Palermo, 2014). The substantial cost of
treatment, combined with the physical and psychological impacts of chronic pain,
illustrate why pediatric chronic pain is an essential topic for current researchers to
address.
Underlying Causes of Chronic Pain
In an effort to remedy chronic pain and lessen its incidence, there is a push by
healthcare professionals to better understand the underlying causes of chronic pain
conditions as a way to proactively address it. If clinicians are better able to identify
anything that can influence both the onset and treatment of chronic pain, it can lead
directly to for efficient management. One way to further our understanding of the
2
underlying causes of chronic pain is through examining specific events that trigger the
onset of pain.
Injury: One of the most researched events is the study of pain development
following varying severities of injury. This topic can be easily studied because the
presence of an injury is readily apparent, the severity of the injury can measured, and the
connection between injury and developing pain condition is usually very clear in most
cases. For example, a recent study measured the onset of widespread pain following
motor vehicle collisions with nearly 8% of participants reporting widespread pain twelve
months following their accident (Wynne-Jones, Jones, Wiles, Silman, & Macfarlane,
2006). This study also identified risk-factors that put patients at a higher risk of chronic
pain following the initial injury such as pre-collision health-seeking behavior, precollision somatization, perceived initial injury severity, and older age.
Another study performed by Jenewein, et al. looked at any accident-related pain
(as opposed to the previous study that limited the scope of their work to “wide-spread
pain”) following the initial injury. This study found that 44% of individuals that sustained
injuries in a motor vehicle accident still reported related pain three years following the
accident (Jenewein et al., 2009). This study went even further to not only look at the rates
of pain at follow-up, but also to look at the effects that this lingering pain had on the
psychological outcomes of the patients included. What the study found was that
individuals with chronic pain following the accident showed significantly more
symptoms of PTSD, depression, and anxiety, along with more disability and days missed
from work (Jenewein et al., 2009).
3
One last injury related study looked at the effects that trauma and injuries have on
chronic pain patients in a slightly different way. These researchers started with a
population of patients with fibromyalgia and investigated whether or not physical trauma
precipitated the onset of their illness (Al-Allaf et al., 2002). This method of starting with
a population of patients rather than starting with a population of individuals who
experienced a given event is more in line with the methods that will be used within the
current study. In this study of fibromyalgia patients, roughly 24% were found to have
experienced serious physical trauma in the 6 months prior to the onset of their disease
(Al-Allaf et al., 2002). This study analyzed a population of pain patients who experienced
a specific event in the months leading up to their disease, rather than analyze a population
of people who experienced a specific event and measure how many of those individuals
developed a chronic pain condition, which is a key differentiation to make in this case, as
those are two separate questions being asked. As stated before, this paper will deal with
the question of what percentage of a population of chronic pain patients has experienced
an event prior to the onset of their pain condition and what type of event they
experienced.
Surgery: Another major event type that will be studied in this paper is surgery and
the development of postoperative pain. In the United States, roughly 73 million surgeries
are performed every year with an estimated 75% of these patients experiencing some
level of pain following the procedure (Apfelbaum, Chen, Mehta, & Gan, 2003). While
postoperative pain can be somewhat expected following complex procedures, in many
cases, this pain can persist longer than anticipated, leading to a decreased quality of life
4
for the patient. Clinical complications that can result in chronic pain following failed
surgical procedures include things such as deep vein thrombosis, coronary ischemia,
pulmonary embolism, myocardial infarction, poor wound healing, and pneumonia
(Apfelbaum et al., 2003).
Post-operative pain is generally considered to have become chronic if the pain
has: 1) persisted more than two months following surgery, and 2) can be attributed
directly to the surgical procedure without the possibility of it being present due to any
preexisting condition (Macrae, 2001). In an older survey study preformed in the UK that
studied a population of patients who frequented pain clinics in Scotland and Northern
England, it was determined that roughly 20% of patients attending these clinics attributed
the cause of their pain to complications from surgical procedures (Macrae, 2001). In
more recent studies on postoperative pain (Neil & Macrae, 2009), the incidence rates of
chronic pain development vary widely based on procedure type:
•
20-50% of patients develop chronic pain following mastectomy.
•
5-65% of patients develop chronic pain following thoracotomy.
•
50-85% of patients develop chronic pain following amputations.
•
5-35% of patients develop chronic pain following open inguinal hernia repair.
Clearly, the rate of pain development following surgical procedures can vary greatly
depending on both the type of surgery being performed and the complexity of the
individual case, but despite these variations in risk, the connection between surgery and
chronic pain development is undeniable and warrants more research into what can be
done to lower these incidence rates.
5
Infection/illness and chronic disease: Two of the last event types that will be
contained within this study are infection/illness events and chronic disease events. In
these two scenarios, chronic pain is a symptom that results from the onset of either a
transient infection or illness, or a more permanent/incurable chronic disease. The number
of chronic diseases and illnesses that cause chronic pain is far too high to attempt to list
within this paper. There is a wide range of incidence rates for multiple different
conditions that vary based on what demographic is studied and what specific conditions
are measured. However, what can be illustrated is the prevalence of chronic conditions in
our society and whether the incident rate of these conditions is trending up or down. A
2012 study conducted by the CDC on chronic conditions among US adults found that
roughly half (49.8%) of this population had at least one chronic health condition (Ward,
Schiller, & Goodman, 2014). In fact, of this total population of Americans, 24.3% had
one condition, 13.8% were found to have two conditions, and about 11.7% had three or
more, with all of these percentages being on the rise from just two years prior at a
statistically significant rate (Ward et al., 2014). All of this data on the increasing trend of
chronic conditions within different populations just further reiterates the need for a better
understand of chronic pain disorders and how to manage them.
Spontaneous Onset of Chronic Pain
While it is important to understand the events that can trigger the onset of chronic
pain, it is also important to recognize that chronic pain conditions can occur
spontaneously. A 2009 review study on Complex Regional Pain Syndrome (CRPS) found
6
that 7% of CRPS patients in the study reported the onset of their condition happened
without any known eliciting event (de Rooij et al., 2010). Not only was there a subset of
this patient population without an event that preceded the start of their CRPS symptoms,
but compared to non-spontaneous cases, these spontaneous onset patients were on
average 9 years younger at diagnosis and had almost a year and a half longer median
disease duration (de Rooij et al., 2010). The findings of this study have a major influence
to the hypothesis of this paper that patients with insidious onset chronic pain will
experience less improvement at follow-up compared to patients that have a known
precipitating event. The study performed by Rooij, et al. suggested that the longer disease
duration might be due to a delay in diagnosis because of the less clear identification of
the disease without a clear inciting event (de Rooij et al., 2010). However, while the 2009
study offered a good look into what could possible be expected for this current study, it
did not encompass multiple pain conditions and was limited to a group of CRPS patients.
Aims and Hypotheses
The current study will take a comprehensive look at the incidence of precipitating
events in all types of chronic pain conditions, as well as the effects that these
precipitating events have on treatment outcomes in various patient subsets. This study
compares all different chronic pain conditions and analyzes the presence and type of
precipitating events that preceded the chronic pain.
In the context of this study, a precipitating event is defined as a clear incident tied
to the onset of an individual’s pain. This event can be injury-related, related to a chronic
7
disease or illness, or be entirely unidentifiable in certain cases. This study will examine
the relative frequency of pediatric chronic pain cases that can be attributed to a
precipitating event and attempt to determine whether or not the presence of a
precipitating event is associated with patient clinical outcomes. The aims of the current
study are to:
1. To measure the prevalence of precipitating events in pediatric chronic pain
patients.
2. To compare pain and functional disability outcomes at evaluation and 4-month
follow up by presence and type of precipitating event.
We hypothesize that there will be a high frequency (greater than half) of chronic
pain patients that experienced a precipitating event prior to the onset of their chronic pain
disorder. We also believe that due to the reasoning presented in the Rooij, et al. study (de
Rooij et al., 2010), along with higher stress levels due to unknown onset of pain, patients
without a definable precipitating event in the medical history will experience higher pain
levels and less functional improvement at follow up than patients without precipitating
events present in their background. Finally, we hypothesize that because of the
fundamental differences between event types, some groups will experience significantly
more or less pain and disability than others.
The hope is that by studying precipitating events in chronic pain patients, health
care providers can better predict patient outcome based on the preceding incident that
caused the pain. If the forecasting information from this study is used in conjunction with
8
the appropriate pain treatment strategies, treatment of children with chronic pain can
potentially be streamlined and more efficient.
9
METHODS
Participants
For the purposes of this study, a retrospective chart review was performed on 401
adolescents, ages 6-19, who presented to a tertiary care chronic pain clinic. The patients
included in the study were evaluated at this tertiary care clinic by a physician, physical
therapist, and psychologist, and completed questionnaire data prior to a clinical interview.
Among these 401 patients, four month follow up disability and pain measures were
collected for 187 of the patients and used for evaluating treatment success.
Measures
There were multiple measures included in this study that were found either within
the medical record or taken from the baseline or follow up measures that were filled out
by the patient.
Demographic and medical variables: Demographic and medical variables were
extracted from patient clinical charts.
Precipitating event: Precipitating event was coded from the medical record by the
researchers, and to ensure consistency of event designation among multiple patients,
multiple event coders overlapped on the same patients, and any discrepancies were
discussed and standardized for all similar patients. There were six event categories used
for the purposes of this study:
•
Surgery
•
Injury
10
•
Infection/Illness
•
Chronic Disease
•
Other
•
No Event Identified
The event type was coded based on the details of both the physician and psychologist
note within the medical records. Information within these written evaluations, as well as
information included in psychological measures filled out by either the patient or
psychologist, was interpreted by the researchers before deciding on the appropriate event
code designation. If there was no clear precipitating event to the patient’s pain complaint,
then the patient would be coded as “no event identified.”
Pain Diagnoses: Using the diagnoses and pain complaints listed in the patient’s
charts, the patients in this study were grouped into five different pain diagnosis groups
for the purposes of this study (localized musculoskeletal pain, neurological pain,
widespread musculoskeletal pain, abdominal pain, and headache related pain). These five
pain diagnosis groupings are what will be used for analysis throughout the study.
Pain intensity: Children were asked during their visit to the pain clinic to provide
their current average pain rating on a standard 11-point numeric scale from 0 (no pain) to
10 (worst possible pain) (von Baeyer, 2009).
Functional disability: The Functional Disability Inventory (FDI) ((Walker &
Greene, 1991), (Claar & Walker, 2006)) is a 15-item questionnaire that measures a
patients’ perception of how much difficulty they’ve had functioning in both physical and
psychosocial ways over the past two weeks due to their physical condition. Scores are
11
calculated by summing all of the items, with a higher total score representing greater
disability. A total score less than 13 indicates low disability and a score greater than or
equal to 30 indicates high disability (Kashikar-Zuck et al. 21458162).
General anxiety: The Revised Children’s Manifest Anxiety Scale (RCMAS)
(Reynolds & Richmond, 2008) is a 45-item questionnaire used to determine child anxiety
levels. All items are summed for a raw total anxiety score. Higher scores represent
greater anxiety symptoms.
Depressive symptoms: The Children’s Depression Inventory (CDI-2) (Kovacs,
1985) is a 28-item questionnaire that is used to measure child depression symptoms.
Higher scores represent a greater number of depressive symptoms.
Children’s somatization inventory (CSI): The CSI (Walker, Garber, & Greene,
1991) evaluates the severity of general pediatric somatic symptoms, like weakness or
dizziness, that may not be directly caused by their pain condition (Walker et al., 1991).
Patients evaluated their experience with 35 different somatic symptoms in the past two
weeks using a 5-point scale ("not at all" (0) to "a whole lot" (4)). Scores are calculated by
summing all the items, and higher scores represent higher levels of somatic symptoms
(Walker et al., 1991).
Child fear of pain: The Fear of Pain Questionnaire for children (FOPQ-C)
(Simons, Sieberg, Carpino, Logan, & Berde, 2011) is a 24-item questionnaire on a 5point scale that assesses pain-related fears in children. Higher score respresent greater
fear of pain. There are two subscales within the measure: Fear of Pain (13 items), which
is a measure of distress in children caused by their pain symptoms, and Avoidance of
12
Activities (11 items), which evaluates avoidance behavior towards certain activities as a
result of fear of pain.
School functioning: The Pediatric Quality of Life Inventory (PedsQL) (Varni,
Seid, & Kurtin, 2001; Varni, Seid, & Rode, 1999) is a 23-item questionnaire that
evaluates the quality of multiple areas of a child’s life. Five of the items within this scale
makeup what is known as the School Functioning subscale, which was used for the
purposes of this study. A higher total score on the measure indicates better school
functioning.
Pain catastrophizing: The Pain Catastrophizing Scale, child report (PCS-C)
(Crombez et al., 2003) is a 13-item questionnaire that measures negative thinking
associated with pain. Higher scores represent greater catastrophizing symptoms.
Statistical Analyses
There were multiple statistical methods used in order to accomplish the two
separate aims of this study. For the first aim of measuring and describe the prevalence of
precipitating events in the given population, the frequencies and distributions of multiple
variables (precipitating event, event type, pain diagnosis, location of pain, pain duration,
age, and gender) were measured.
To accomplish the second aim of the study, which was to compare pain,
functional disability, depression, and somatic symptoms at evaluation and 4-month
follow up, one-way ANOVAs, T-tests, and repeated measure ANOVAs were used. The
one-way ANOVA was used to examine differences across all event groups (surgery,
13
injury, infection/illness, chronic disease, other, and no event) based on multiple outcome
variables (typical pain, FDI, school functioning, depression, anxiety, somatization, fear of
pain, and pain catasrophizing). These tests were run twice, once to compare differences at
baseline, and again to compare difference at 4 month follow up. The T-tests allowed us to
create dichotomous variables from the larger event categories and compare them against
the rest of our sample looking for significant differences among the same variables used
in the one-way ANOVA. Once again, the tests were run twice to account for the 4-month
follow up. Finally, repeated measure ANOVAs were used to compare improvement rates
in FDI and typical pain based on four month follow up data. These tests were run for the
four largest dichotomous categories (precipitating event, injury, infection, and chronic
disease).
14
RESULTS
Participants
Of the 401 study participants, there were 303 girls (75.6%) and 98 boys (24.4%)
included the study. Of these participants, the average age was 13.8 years old and the
majority of patients were Caucasian (92.7%). The pain diagnoses within the group
included patients with musculoskeletal disorders, CRPS/RSD, neuropathic disorders (not
CRPS), fibromyalgia, juvenile rheumatoid arthritis, functional abdominal pain, IBS,
headache, endometriosis, gynecological disorders (not endometriosis), genitourinal
disorders, Ehlers-Danlos syndrome, postural orthostatic tachycardia syndrome,
hypermobility, and pain amplification disorders. These pain diagnoses were divided into
five separate groups for the purposes of this study. The median pain duration within the
group was 13.5 months.
15
Group Name
Pain Diagnoses
Localized
Musculoskeletal
Single limb or joint, low back, chest pain
Neuropathic
CRPS, neuralgia, pain amplification
Diffuse Musculoskeletal
Widespread musculoskeletal pain, Postural
Orthostatic Tachycardia Syndrome (POTS)
with musculoskeletal pain, Ehlers Danlos
Syndrome (EDS), joint hypermobility,
fibromyalgia
Abdominal
Functional abdominal pain (FAP), Irritable
Bowel Syndrome (IBS), Inflammatory
Bowel Disease (IBD), Endometriosis
Headache
Migraine, tension, chronic daily headache,
post-traumatic headache
Table 1. Groupings of Pain Diagnoses. There were multiple pain diagnoses present in
the charts of the study patients. Grouping the patients into these separate groups will
allow for easier analysis of precipitating event data that is related to pain diagnoses.
16
Incidence of Precipitating Events
Roughly two thirds (66.1%) of patients had a precipitating event prior to their
pain onset. Of these 265 patients with a precipitating event, injury was the most common
(36.4%), followed by chronic disease (15.2%), infection/illness (8.5%), and surgery
(5.0%). There were 136 patients (33.9%) without an identified precipitating event prior to
pain onset. Four patients (1%) had precipitating events that did not fit the description of
any other precipitating event category, so they were coded as “other” within the database
(the patients in this group were excluded from the chi-squared calculations as well as the
one-way ANOVA calculations due to the low sample size).
When looking at a breakdown of event groupings by pain diagnoses, a chisquared test showed significant differences in proportions of patients in several groups
(X2(16) = 121.3, p < 0.001). There were multiple aspects of this breakdown that
contributed to this result. Patients that experienced injury events prior to their pain were
significantly more likely to develop neuropathic pain, and significantly less likely to
develop diffuse musculoskeletal pain or abdominal pain. Patients that experienced illness
or infection events were significantly more likely to develop abdominal pain, and patients
that experienced no event but still had chronic pain were significantly more likely to have
neuropathic pain. And finally, patients with a chronic disease event were significantly
more likely to develop diffuse musculoskeletal pain and significantly less likely to
develop neuropathic pain.
17
Variable
Localized
Musculoskeletal
Pain
Neuropathic
Pain
Diffuse
Musculoskeletal
Pain
Abdominal
Pain
HeadacheRelated Pain
Surgery
n (%)
Injury
n (%)
Infection/
Illness
n (%)
Chronic
Disease
n (%)
No event
n (%)
10
(50.0%)
58
(39.7%)
7
(20.6%)
25
(41.0%)
66
(48.5%)
4
(20.0%)
74**
(50.7%)
4
(11.8%)
3*
(4.9%)
23*
(16.9%)
1
(5.0%)
2*
(1.4%)
7
(20.6%)
18**
(29.5%)
18
(13.2%)
3
(15.0%)
3*
(2.1%)
11**
(32.4%)
13
(21.3%)
22
(16.2%)
2
(10.0%)
9
(6.2%)
5
(14.7%)
2
(3.3%)
7
(5.1%)
Note. % indicates the portion of event grouping that contributed to a given pain diagnosis
Note. ** indicates an accompanying standard residual > 2.0 and * indicates an
accompanying standard residual < -2.0
Table 2. Breakdown of Event Type by Subsequent Pain Diagnosis. This table shows
the breakdown of all patients in the study (excluding patients contained in the “other”
event type) by both event type and pain diagnosis.
18
Differences in Functioning Across Participating Events: Baseline
Comparing all participating events: Using one-way ANOVAs, there were no
statistically significant differences among precipitating events for each emotional and
functional variable at the time of the pain clinic evaluation. Specifically, none of the
patients categorized among the six precipitating event types (surgery, injury,
infection/illness, chronic disease, other, no event) reported significantly different typical
pain, functional disability, school functioning, depression, anxiety, somatization, fear of
pain, or pain catastrophizing using this omnibus test.
19
Variable
Surgery Injury Infection/
Event Event
Illness M (SD)
M
Event (SD)
M (SD) Chronic No Event Disease Identified Event M (SD) M (SD) F
Typical Pain
(n=366)
5.53
(1.82)
6.25
(2.08)
5.25
(2.28)
5.61
(2.17)
5.88
(1.97)
2.18
Functional
Disability
(n=396)
21.9
(10.5)
24.1
(11.5)
21.4
(11.6)
20.5
(12.1)
20.3
(11.6)
2.20
School
Functioning
(n=262)
63.8
(21.8)
60.0
(20.8)
54.3
(20.7)
50.9
(21.2)
58.8
(20.2)
1.77
Depression
(CDI) (n=390)
54.1
(12.4)
57.6
(13.1)
56.1
(11.4)
55.9
(11.4)
56.3
(13.2)
0.47
Anxiety
(n=383)
48.9
(11.7)
50.1
(11.8)
49.2
(10.6)
52.2
(12.1)
48.7
(11.9)
0.98
Somatization
(CSI) (n=386)
29.1
(13.7)
26.9
(16.7)
33.1
(17.8)
28.1
(15.8)
27.8
(16.3)
0.94
Fear of Pain
(n=380)
50.4
(20.7)
44.7
(22.0)
46.3
(19.6)
47.5
(22.2)
44.1
(20.0)
0.87
Pain
Catastrophizing
(PCS) (n=306)
29.8
(13.7)
31.4
(11.8)
27.3
(14.5)
31.7
(12.4)
28.6
(12.2)
1.19
Note. *p < .05; **p < .01
Table 3. One-Way ANOVAs at Baseline. This table contains the result of one-way
ANOVAs examining differences in psychological variables by different event categories
at baseline.
20
Comparing each participating event to all other patients: When examining each
specific participating event to all other patients using Independent Samples t-tests, some
differences did emerge. At baseline, patients with a precipitating event had a statistically
significantly higher functional disability (M = 22.7, SD = 11.6) than patients without a
precipitating event ((M = 20.3, SD = 11.6), t(394) = 1.98, p = 0.049). Patients with an
injury event had a statistically significantly higher average pain score (M = 6.25, SD =
2.08) and functional disability (M = 24.1, SD = 11.5) than patients with a precipitating
event that was not an injury (((M = 5.71, SD = 2.04), t(364) = 2.44, p = 0.015) and ((M =
20.6, SD = 11.5), t(394) = 2.93, p = 0.004), respectively). Lastly, patients with a chronic
disease event had a statistically significant lower school functioning score (M = 50.9, SD
= 21.2) than patients with a precipitating event that was not a chronic disease ((M = 59.0,
SD = 20.5), t(260) = -2.21, p = 0.028).
21
Variable
Precipitating
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=366)
5.91 (2.12)
5.88 (1.97)
0.14
Functional Disability (n=396)
22.7 (11.6)
20.3 (11.6)
1.98*
School Functioning (n=262)
57.3 (21.1)
58.8 (20.2)
-0.59
Depression (CDI) (n=390)
56.8 (12.4)
56.3 (13.2)
0.36
Anxiety (n=383)
50.4 (11.7)
48.7 (11.9)
1.39
Somatization (CSI) (n=386)
28.2 (16.4)
27.8 (16.3)
0.21
Fear of Pain (n=380)
46.2 (21.6)
44.1 (20.0)
0.90
Pain Catastrophizing (PCS)
(n=306)
31.1 (12.5)
28.6 (12.2)
1.66
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 4. Baseline Precipitating Event T-test. This table contains the results of a T-test
examining differences in baseline psychological variables between patients with a
precipitating event and all other patients that did not experience a precipitating event.
22
Variable
Injury
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=366)
6.25 (2.08)
5.71 (2.04)
2.44*
Functional Disability (n=396)
24.1 (11.5)
20.6 (11.5)
2.93**
School Functioning (n=262)
60.0 (20.8)
56.6 (20.7)
1.26
Depression (CDI) (n=390)
57.6 (13.1)
56.1 (12.4)
1.10
Anxiety (n=383)
50.1 (11.8)
49.7 (11.7)
0.33
Somatization (CSI) (n=386)
26.9 (16.7)
28.7 (16.2)
-1.05
Fear of Pain (n=380)
44.7 (22.0)
46.0 (20.5)
-0.57
Pain Catastrophizing (PCS) (n=306)
31.4 (11.8)
29.5 (12.8)
1.28
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 5. Baseline Injury Event T-test. This table contains the results of a T-test
examining differences in baseline psychological variables between patients with an injury
event and all other patients that did not experience an injury event.
23
Variable
Infection
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=366)
5.25 (2.28)
5.96 (2.04)
-1.87
Functional Disability (n=396)
21.4 (11.6)
21.9 (11.6)
-0.25
School Functioning (n=262)
54.3 (20.7)
58.2 (20.8)
-0.88
Depression (CDI) (n=390)
56.1 (11.4)
56.7 (12.8)
-0.23
Anxiety (n=383)
49.2 (10.6)
49.9 (11.9)
-0.35
Somatization (CSI) (n=386)
33.1 (17.8)
27.6 (16.2)
1.80
Fear of Pain (n=380)
46.3 (19.6)
45.4 (21.2)
0.23
Pain Catastrophizing (PCS) (n=306)
27.3 (14.5)
30.5 (12.3)
-1.21
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 6. Baseline Infection Event T-test. This table contains the results of a T-test
examining differences in baseline psychological variables between patients with an
infection event and all other patients that did not experience an infection event.
24
Variable
Chronic
Disease
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=366)
5.61 (2.17)
5.95 (2.05)
-1.14
Functional Disability (n=396)
20.5 (12.1)
22.1 (11.6)
-0.97
School Functioning (n=262)
50.9 (21.2)
59.0 (20.5)
-2.21*
Depression (CDI) (n=390)
55.9 (11.4)
56.8 (12.9)
-0.48
Anxiety (n=383)
52.2 (12.1)
49.4 (11.7)
1.69
Somatization (CSI) (n=386)
28.1 (15.8)
28.1 (16.5)
0.03
Fear of Pain (n=380)
47.5 (22.2)
45.1 (20.9)
0.76
Pain Catastrophizing (PCS) (n=306)
31.7 (12.4)
30.0 (12.5)
0.81
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 7. Baseline Chronic Disease Event T-test. This table contains the results of a Ttest examining differences in baseline psychological variables between patients with a
chronic disease event and all other patients that did not experience a chronic disease
event.
25
Differences in Functioning Across Participating Events: 4-Month Follow-Up
Comparing all participating events: Once again, using one-way ANOVAs, there
were no statistically significant differences among precipitating events for each emotional
and functional variable roughly four months after their pain clinic evaluation. Again,
none of the patients categorized among the six precipitating event types (surgery, injury,
infection/illness, chronic disease, other, no event) reported significantly different typical
pain, functional disability, school functioning, depression, anxiety, somatization, fear of
pain, or pain catastrophizing using this omnibus test.
26
Variable
Surgery Injury Infection/
Event Event
Illness
M (SD)
M
Event
(SD)
M (SD)
Chronic
Disease
Event
M (SD)
No Event
Identified
M (SD)
F
Typical Pain
(n=186)
5.17
(2.32)
4.92
(3.02)
4.20
(2.54)
4.52
(2.70)
4.70
(2.56)
0.30
Functional
Disability
(n=194)
19.7
(15.6)
13.6
(11.3)
12.8
(9.77)
16.7
(12.0)
11.8
(10.8)
1.35
School
Functioning
(n=182)
55.0
(31.8)
63.2
(23.3)
59.0
(21.2)
60.6
(23.7)
63.8
(23.2)
0.33
Depression
(CDI) (n=179)
51.0
(15.2)
53.7
(11.7)
50.2
(7.78)
58.0
(13.5)
52.3
(10.6)
1.48
Anxiety
(n=185)
44.5
(14.8)
46.9
(11.1)
45.3
(12.1)
52.1
(14.6)
43.8
(11.1)
2.19
Somatization
(CSI) (n=194)
18.3
(14.8)
16.3
(15.7)
23.1
(15.5)
22.0
(17.1)
17.5
(14.9)
1.08
Fear of Pain
(n=186)
33.5
(34.8)
31.7
(22.2)
32.9
(19.6)
42.1
(25.1)
33.9
(21.8)
0.96
Pain
Catastrophizing
(PCS) (n=186)
22.7
(18.2)
21.0
(13.3)
19.3
(11.8)
24.6
(13.8)
21.6
(13.3)
0.44
Note. *p < .05; **p < .01
Table 8. One-Way ANOVAs at Follow-Up. This table contains the result of one-way
ANOVAs examining differences in psychological variables by different event categories
at four-month follow-up.
27
Comparing each participating event to all other patients: At follow-up, there
were once again significant findings amount specific precipitating event groupings
compared to all other patients. Patients with a precipitating event had a significantly
higher anxiety level (M = 47.7, SD = 12.2) than patients without a precipitating event
((M = 43.8, SD = 11.1), t(183) = 2.09, p = 0.038). Patients with a chronic disease event
had significant higher anxiety (M = 52.1, SD = 14.6) and depression (M = 58.0, SD =
13.4) levels than patients without a chronic disease event ((M = 45.6, SD = 11.4), t(183)
= 2.48, p = 0.014) and ((M = 52.8, SD = 11.0), t(177) = 2.07, p = 0.040), respectively).
28
Variable
Precipitating
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=186)
4.79 (2.85)
4.70 (2.56)
0.20
Functional Disability (n=194)
14.5 (11.5)
11.8 (10.8)
1.59
School Functioning (n=182)
61.5 (23.5)
63.8 (23.2)
-0.62
Depression (CDI) (n=179)
54.1 (11.8)
52.3 (10.6)
0.98
Anxiety (n=185)
47.7 (12.2)
43.8 (11.1)
2.09*
Somatization (CSI) (n=194)
18.4 (16.0)
17.5 (14.9)
0.39
Fear of Pain (n=186)
34.1 (23.3)
23.3 (21.8)
0.05
Pain Catastrophizing (PCS) (n=186) 21.6 (13.4)
21.6 (13.3)
0.003
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 9. Follow-Up Precipitating Event T-test. This table contains the results of a Ttest examining differences in follow-up psychological variables between patients with a
precipitating event and all other patients that did not experience a precipitating event.
29
Variable
Injury
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=186)
4.92 (3.02)
4.64 (2.54)
0.68
Functional Disability (n=194)
13.6 (11.3)
13.5 (11.4)
0.02
School Functioning (n=182)
63.2 (23.3)
61.5 (23.5)
0.47
Depression (CDI) (n=179)
53.7 (11.7)
53.4 (11.3)
0.16
Anxiety (n=185)
46.9 (11.1)
46.0 (12.6)
0.51
Somatization (CSI) (n=194)
16.3 (15.7)
19.4 (15.4)
-1.39
Fear of Pain (n=186)
31.7 (22.2)
35.8 (23.0)
-1.22
Pain Catastrophizing (PCS) (n=186)
21.0 (13.3)
22.1 (13.4)
-0.56
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 10. Follow-Up Injury Event T-test. This table contains the results of a T-test
examining differences in follow-up psychological variables between patients with an
injury event and all other patients that did not experience an injury event.
30
Variable
Infection
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=186)
4.20 (2.54)
4.81 (2.77)
-0.82
Functional Disability (n=194)
12.8 (9.77)
13.6 (11.5)
-0.30
School Functioning (n=182)
59.0 (21.2)
62.5 (23.6)
-0.56
Depression (CDI) (n=179)
50.2 (7.78)
53.8 (11.7)
-1.21
Anxiety (n=185)
45.3 (12.1)
46.5 (12.0)
-0.37
Somatization (CSI) (n=194)
23.1 (15.5)
17.7 (15.5)
1.33
Fear of Pain (n=186)
32.9 (19.6)
34.1 (23.0)
-0.20
Pain Catastrophizing (PCS) (n=186)
19.3 (11.8)
21.8 (13.5)
-0.69
Note. *p < .05; **p < .01; T-tests are two-tailed.
Table 11. Follow-Up Infection Event T-test. This table contains the results of a T-test
examining differences in follow-up psychological variables between patients with an
infection event and all other patients that did not experience an infection event.
31
Variable
Chronic
Disease
Event
M (SD)
All Other
Groups
M (SD)
t
Typical Pain (n=186)
4.52 (2.70)
4.79 (2.76)
-0.44
Functional Disability (n=194)
16.7 (12.0)
13.1 (11.2)
1.46
School Functioning (n=182)
60.6 (23.7)
62.5 (23.4)
-0.36
Depression (CDI) (n=179)
58.0 (13.4)
52.8 (11.0)
2.07*
Anxiety (n=185)
52.1 (14.6)
45.6 (11.4)
2.48*
Somatization (CSI) (n=194)
22.0 (17.1)
17.6 (15.3)
1.30
Fear of Pain (n=186)
42.1 (25.1)
32.9 (22.2)
1.83
Pain Catastrophizing (PCS) (n=186) 13.8 (13.8)
Note. *p < .05; **p < .01; T-tests are two-tailed.
13.2 (13.2)
1.14
Table 12. Follow-Up Chronic Disease Event T-test. This table contains the results of a
T-test examining differences in follow-up psychological variables between patients with
a chronic disease event and all other patients that did not experience a chronic disease
event.
32
Examining Trajectories of Pain and Disability
In the repeated measures ANOVAs, trajectories of pain and disability did not
differ between patients with and without a precipitating event. There was an interaction
observed for injury status, patients with injuries reported greater improvement in
functional disability at follow-up (time x injury) F(1, 190)=6.07, p<.05. There was also
an interaction observed for chronic disease status, wherein patients with chronic disease
reported less improvement in disability (time x chronic disease), F(1, 190)=4.64, p<.05.
No other interactions were significant for disability or pain.
33
30 Mean FDI Value 25 20 24.1 19.3 13.7 15 13.4 10 Injury Event Non-­‐Injury Event 5 0 Baseline Follow-­‐Up Time Figure 1. Trajectory of Functional Disability Change in Injury and Non-Injury
Patients. The above figure illustrates the trajectories of functional disability
improvement in both patients with and without the presence of an injury event prior to
the onset of their chronic pain condition. These results were obtained using a multiple
regression ANOVA.
34
Mean FDI Value 25 20 21.6 18.7 16.3 13.2 15 Chronic Disease Event 10 Non-­‐Chronic Disease Event 5 0 Baseline Follow-­‐Up Time Figure 2. Trajectory of Functional Disability Change in Chronic Disease and NonChronic Disease Patients. The above figure illustrates the trajectories of functional
disability improvement in both patients with and without the presence of a chronic
disease event prior to the onset of their chronic pain condition. These results were
obtained using a multiple regression ANOVA.
35
DISCUSSION
This study utilized a variety of different statistical methods to accomplish the two
aims of measuring the prevalence of precipitating events and characterizing the effects
that these types of events have on patient outcomes. Approximately 66% of patients
analyzed reported an event that precipitated the onset of their pain. The presence of a
precipitating event had varied effects on the treatment outcomes of patients at four-month
follow-up.
Aim I: Measuring the Prevalence of Precipitating Events
The most significant finding that emerged from the frequency data on the
prevalence of precipitating events was the fact that 265 (66%) of the patients in this study
were found to have a precipitating event prior to the onset of their chronic pain. Of these
265 patients, the largest event group was the injury grouping (146 patients), followed by
the chronic disease group (61 patients), the infection/illness group (34 patients), the
surgery group (20 patients), and finally the “other” category (4 patients who could not be
classified into one of the precipitating event groups. Precipitating events included sexual
assault, school change, etc.).
The results from this part of the study on the prevalence of precipitating events
were significant because they suggested that within a large random sampling of pediatric
chronic pain patients, a majority of these patients would have experienced a precipitating
event that most likely caused the onset of their chronic pain.
36
There were 136 (~34%) patients who were determined by coders to not have a
precipitating event that caused the onset of their chronic pain. These patients usually had
insidious onset of their pain, or incidents leading up to the pain were not determined to
have directly caused the chronic pain. Some examples of cases in the “no event
identified” category included patients with sudden onset of migraine headaches or
abdominal pain, joint or limb pain not caused by injury, illness, or disease, and full body
pain with clear etiology.
So while a majority of patients within the study did have a precipitating event
prior to the onset of chronic pain, there was still a large group of patients who were found
to have no precipitating event within their chart. This will be further discussed later, but
one limitation of the study was only having access to the electronic chart records as
opposed to being able to interview the patients themselves. It is reasonable to assume the
possibility that some of the patients within the “no event identified group” did in fact
have a precipitating event, however, that event did not make it into the medical record. It
is possible that having the chance to interview the patients in person would have revealed
more information about the presence of a precipitating event.
The chi-squared data showed that there were in fact significant differences in
proportions of patients in several groups. There were multiple cases of certain events
being more or less likely to cause certain chronic pain conditions. The injury group was
one of the most polarizing in that it showed injury events being significantly more likely
to cause neuropathic pain, and significantly less likely to cause diffuse musculoskeletal
pain or abdominal pain. This is understandable as injury is one of the leading causes of
37
CRPS, which is a neuropathic condition. While injury also caused a large number
localized musculoskeletal pain patients and a small number of headache-related pain
patients, there numbers were not shown to be significant within the pain diagnosis group.
One other event group that resulted in multiple significant relationships was the
chronic event group. In this category, experiencing a chronic disease was significantly
more likely to result in diffuse musculoskeletal pain, and significantly less likely to result
in neuropathic pain. This result can be explained by looking at the different conditions
within the diffuse musculoskeletal pain group. Conditions like fibromyalgia, EDS, and
POTS were categorized as being a diffuse musculoskeletal pain diagnosis, and all of
these diagnoses are chronic conditions that would have been classified as chronic events.
The surgery event category did not have any significant correlation to any
particular pain diagnosis, and the infection/illness and “no event” categories only had one
significant correlation each (significantly more likely to cause abdominal pain and
significantly less likely to cause neuropathic pain, respectively).
Aim II: Comparing Outcomes at Baseline and Follow-Up
Before the data collection for this study began, we had hypothesized that patients
with a definable precipitating event will experience lower pain levels and greater
improvement at follow up compared to patients without a discernable precipitating
events. The idea behind this hypothesis came in part from the Rooij, et al. study cited
earlier in the paper, which suggested that in the case of chronic pain with a spontaneous
onset, patients will not only have higher levels of anxiety and stress, but these patients
38
will also be more difficult to diagnose and treat, therefore creating more resistance to
typical methods of treatment (de Rooij et al., 2010). However, the data that was collected
in this study did not support this hypothesis.
Comparing all participating events: When using the one-way ANOVA to
compare all precipitating events across all emotional and functional variables (at both the
time of the pain clinic evaluation and at four-month follow-up), there were no significant
differences between precipitating event categories for any of the variables at either time
point. This lack of noticeable variation between the event categories could have been due
to several reasons. One possible explanation could be that although the overall size of the
study sample was large, the sample size within each individual event category was too
small to detect any differences. This result also may be a sign that while there are unique
qualities to different event categories that show up in the independent sample t-tests, the
specific type of precipitating event matters less and that each event type will produce
similar outcomes when compared to any other singular grouping.
Comparing each participating event to all other patients: In an analysis of each
event type compared to all other patients using independent sample t-tests at baseline and
follow-up, there were several significant results that may suggest some event groups have
specific difficulties when compared to the general population of chronic pain patients.
The first result from this analysis was that at baseline, patients with a precipitating
event had a statistically significantly higher functional disability than patients who did
not have a precipitating event present in their chart. This results is indicative of the
baseline values of functional disability, so it does not give any insight to the
39
responsiveness of the patients to treatment, however, it is a significant result because it
shows that the presence of a precipitating event can possibly indicate a more serious
prognosis when it comes to functional disability.
However, there is reason to believe that this result may skewed by the injury
precipitating event category, because compared to all other patients, patients with an
injury event had higher levels of both pain and functional disability at baseline. There
were all different types of serious injuries included in this study, and it is understandable
as to why the average pain and functional disability scores would be higher in this subset
of patients. But because these patients are also coded within the dichotomous variable for
the presence of a precipitating event, the seriousness of this category may contribute to
the previous result of patients with a precipitating event having a higher functional
disability score at baseline.
The final result of these independent sample t-tests for baseline scores was the
discovery that patients with a chronic disease event type had a statistically significant
lower school functioning score than those patients who did not have a chronic disease
event type. The exact reasoning behind this result may become clearer when looking at
the 4-month follow-up independent sample t-test for chronic pain, but even without
looking at that data, there has been ample research into the struggles that children with
chronic illness encounter when it comes to school functioning. Just one example of this
work is 2010 study that looked at quality of life measures in pediatric chronic pain
patients. In this study, the significant effect (p < 0.001) that chronic disease had on school
functioning scores was well documented (Ingerski et al., 2010). All of this research points
40
to a reasonable explanation of why at baseline, patients within the chronic disease event
subset in this study had a lower average school functioning value.
In the follow-up analyses, patients with a precipitating event had a statistically
significantly higher anxiety level than patients who did not experience a precipitating
event prior to the onset of their chronic pain condition. This result is possibly one of the
most significant of the study, as it somewhat refutes the original hypothesis that patients
with a definable precipitating event will experience better outcomes at follow up
compared to patients without a discernable precipitating events. While there were no
other significant differences between “event” and “no-event” patients at follow-up, this
result proves that patients that do have an event present in their chart do in fact have
somewhat of a more negative outcome at follow-up.
When looking at the data, there are a few reasons as to why this may be. It’s
possible that a higher anxiety level comes from the frustration of knowing the cause of
your pain, but still unable to find relief. This result may also be because of the higher
levels of disability at baseline for patients that have an event present, however, there were
no significant different in disability levels within this group at follow up. No matter what
the cause, more research is required to confirm this result, as well as find out what the
underlying cause of it is.
Finally, the last significant result in the follow-up data was patients with a chronic
disease event showing statistically higher anxiety and depression levels than patients with
a precipitating event that was not a chronic disease. This is understandable because of the
significant burden that comes with managing chronic disease successfully. A 2012 study
41
performed by the National Institute of Health examined the coping strategies and
techniques that were most successful in managing chronic illness. The study described
multiple processes that when used together, helped better manage patient outcomes.
Doing things like focusing on direct illness needs and correctly activating healthcare
resources all were shown as effective strategies to living with chronic illness (SchulmanGreen et al., 2012). However, the difficulty in managing chronic disease comes from
learning and practicing these techniques, and it is easy to see how the onset of chronic
disease can lead to elevated levels of anxiety and depression shortly after diagnosis. The
reasoning behind these follow-up results also helps explain the chronic disease results
from the baseline tests. It is understandable that chronic disease patients who are
significantly more depressed or anxious will have lower school functioning and
performance as a result.
Trajectories of pain and disabilities: The final part of the analysis looked at the
trajectories of pain and disability from baseline to four-month follow-up among the major
event-type groupings. The results ultimately showed that patients with injury events
reported greater improvement in functional disability at follow-up, whereas patients with
chronic disease reported less improvement in disability at follow-up. These results can be
explained mainly by looking at the type of event in each individual case. An injury event
in most cases will be something that will hopefully heal over time. Barring setbacks, the
hope is that the patient will ultimately make a good recovery. Obviously this is not the
case in these cases of chronic pain, but it can be assumed that patients will at least have
improved past the initial disability that immediately followed the injury. As opposed to a
42
patient with an injury, a patient with a chronic disease may have no immediate cure, and
while treatment for the symptoms of the disease may be available, the disease is most
likely still present at four-month follow-up, causing significantly less improvement in
functional disability compared to all other event groupings.
Implications
While the implications of how this study will affect the wider field of pediatric
field is not entirely clear, the hope is that the significant results drawn within this study
will influence future direction of chronic pain research. The constant theme that has been
present throughout of this paper has been the idea that a better understanding of chronic
pain onset can lead to improved outcomes of chronic pain patients. So the hope is that the
field of chronic pain research can more directly target areas of need by shedding more
light on what causes chronic pain in multiple different scenarios. For example, if it’s
confirmed through this paper that chronic disease patients who are experiencing pain
have higher levels of anxiety and depression, then maybe it can lead to a change in pain
treatment strategies that allows for more resources to be allocated to pain patients who
have experienced chronic illness. Or if it’s true that chronic pain patients who have
experienced injuries prior to pain onset, then this study can possibly be used to validate
current treatment strategies in this patient subset. Overall, the results of this study can be
used to gain a better understanding of chronic pain, as well as evaluate the different
treatment methods that are used in different chronic pain cases.
43
Limitations and Future Direction
There may be a few different improvements that can be made on this study to
hopefully improve the clarity of the analysis and help draw stronger conclusions. The
first would be to increase the sample size within each event category. While there were
some categories that had a large number of patients, hopefully adding more individuals to
the groups would tell us with more confidence whether or not there are significant
differences among the categories. Also, while it would be impractical on such a large
scale, it would most likely help categorize the patients to have taken the history of illness
directly from them. As stated earlier in the study, having the opportunity to interview the
patients, especially in the ones that would be placed in the “no-event” category, could
possibly reveal more information about patient history that was not present within the
medical record.
Future research into the effects that precipitating events have in pediatric chronic
pain patients should work towards validating the results presented in this study, along
with explaining the reasoning behind the significant results that were found. Future
studies that focus on the new questions presented within this study could go a long way
towards discovering new ways to approach cases of chronic pain. As discussed before,
the significant results that were drawn from this study can be used to not only gain a
better understanding on the different causes of chronic pain, but also to impact clinic care
by serving as a way to evaluate current treatment methods. If this study (along with other
follow-up studies) shows that certain pain groups are not improving at the same rates as
44
others, then maybe this would be evident of flawed or out of date methods of treatment
are being used.
Conclusion
This study was a great first step in determining the effects that the presence of a
precipitating event has on chronic pain treatment outcomes. We determined that a
majority of patients who present with chronic pain do in fact have a precipitating event
that caused the onset of their pain condition. We also discovered multiple variables that
can possibly influence baseline and follow-up measures, as well as the trajectories of
these measures. There is still much more research that is necessary to fully explain and
confirm the results contained within this study, however, hopefully these results can start
changing the thinking on chronic pain cases, as well as improve the treatment outcomes
of chronic pain patients sometime in the future.
45
LIST OF JOURNAL ABBREVIATIONS
Anesth Analg................................................................................Anesthesia and Analgesia
BMC Pediatr.................................................................................................BMC Pediatrics
Br J Anaesth............................................................................British Journal of Anesthesia
Eur J Pain.......................................................................................European Journal of Pain
J Abnorm Child Psychol.........................................Journal of Abnormal Child Psychology
J Nurs Scholarsh...................................................................Journal of Nursing Scholarship
J Pain..............................................................................................................Journal of Pain
J Pediatr..........................................................................................Journal of Pediatric Pain
J Pediatr Psychol.................................................................Journal of Pediatric Psychology
J Psychosom Res...........................................................Journal of Psychosomatic Research
J Rheumatol...................................................................................Journal of Rheumatology
Med Care..........................................................................................................Medical Care
Pain Res Manag..................................................................Pain Research and Management
Prev Chronic Dis.......................................................................Preventing Chronic Disease
46
REFERENCES
Al-Allaf, A. W., Dunbar, K. L., Hallum, N. S., Nosratzadeh, B., Templeton, K. D., &
Pullar, T. (2002). A case-control study examining the role of physical trauma in
the onset of fibromyalgia syndrome. Rheumatology (Oxford), 41(4), 450-453.
Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/11961177
Apfelbaum, J. L., Chen, C., Mehta, S. S., & Gan, T. J. (2003). Postoperative pain
experience: results from a national survey suggest postoperative pain continues to
be undermanaged. Anesth Analg, 97(2), 534-540, table of contents. Retrieved
from http://www.ncbi.nlm.nih.gov/pubmed/12873949
Claar, R. L., & Walker, L. S. (2006). Functional assessment of pediatric pain patients:
psychometric properties of the functional disability inventory. Pain, 121(1-2), 7784. doi:10.1016/j.pain.2005.12.002
Coffelt, T. A., Bauer, B. D., & Carroll, A. E. (2013). Inpatient characteristics of the child
admitted with chronic pain. Pediatrics, 132(2), e422-429. doi:10.1542/peds.20121739
Crombez, G., Bijttebier, P., Eccleston, C., Mascagni, T., Mertens, G., Goubert, L., &
Verstraeten, K. (2003). The child version of the pain catastrophizing scale (PCSC): a preliminary validation. Pain, 104(3), 639-646.
de Rooij, A. M., Perez, R. S., Huygen, F. J., van Eijs, F., van Kleef, M., Bauer, M. C., . . .
Marinus, J. (2010). Spontaneous onset of complex regional pain syndrome. Eur J
Pain, 14(5), 510-513. doi:10.1016/j.ejpain.2009.08.007
Elliott, A. M., Smith, B. H., Penny, K. I., Smith, W. C., & Chambers, W. A. (1999). The
epidemiology of chronic pain in the community. Lancet, 354(9186), 1248-1252.
Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/10520633
Groenewald, C. B., Essner, B. S., Wright, D., Fesinmeyer, M. D., & Palermo, T. M.
(2014). The economic costs of chronic pain among a cohort of treatment-seeking
adolescents in the United States. J Pain, 15(9), 925-933.
doi:10.1016/j.jpain.2014.06.002
Hechler, T., Kanstrup, M., Holley, A. L., Simons, L. E., Wicksell, R., Hirschfeld, G., &
Zernikow, B. (2015). Systematic Review on Intensive Interdisciplinary Pain
Treatment of Children With Chronic Pain. Pediatrics, 136(1), 115-127.
doi:10.1542/peds.2014-3319
47
Ingerski, L. M., Modi, A. C., Hood, K. K., Pai, A. L., Zeller, M., Piazza-Waggoner, C., . .
. Hommel, K. A. (2010). Health-related quality of life across pediatric chronic
conditions. J Pediatr, 156(4), 639-644. doi:10.1016/j.jpeds.2009.11.008
Jenewein, J., Moergeli, H., Wittmann, L., Buchi, S., Kraemer, B., & Schnyder, U. (2009).
Development of chronic pain following severe accidental injury. Results of a 3year follow-up study. J Psychosom Res, 66(2), 119-126.
doi:10.1016/j.jpsychores.2008.07.011
King, S., Chambers, C. T., Huguet, A., MacNevin, R. C., McGrath, P. J., Parker, L., &
MacDonald, A. J. (2011). The epidemiology of chronic pain in children and
adolescents revisited: a systematic review. Pain, 152(12), 2729-2738.
doi:10.1016/j.pain.2011.07.016
Kovacs, M. (1985). The Children's Depression, Inventory (CDI). Psychopharmacol Bull,
21(4), 995-998. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/4089116
Macrae, W. A. (2001). Chronic pain after surgery. Br J Anaesth, 87(1), 88-98. Retrieved
from http://www.ncbi.nlm.nih.gov/pubmed/11460816
Mansfield, K. E., Sim, J., Jordan, J. L., & Jordan, K. P. (2016). A systematic review and
meta-analysis of the prevalence of chronic widespread pain in the general
population. Pain, 157(1), 55-64. doi:10.1097/j.pain.0000000000000314
Neil, M. J., & Macrae, W. A. (2009). Post Surgical Pain- The Transition from Acute to
Chronic Pain. Rev Pain, 3(2), 6-9. doi:10.1177/204946370900300203
Reynolds, C. R., & Richmond, B. O. (2008). Revised Children's Manifest Anxiety Scale,
Second Edition (RCMAS-2), Manual.
Schulman-Green, D., Jaser, S., Martin, F., Alonzo, A., Grey, M., McCorkle, R., . . .
Whittemore, R. (2012). Processes of self-management in chronic illness. J Nurs
Scholarsh, 44(2), 136-144. doi:10.1111/j.1547-5069.2012.01444.x
Simons, L. E., Sieberg, C. B., Carpino, E., Logan, D., & Berde, C. (2011). The Fear of
Pain Questionnaire (FOPQ): assessment of pain-related fear among children and
adolescents with chronic pain. The Journal of Pain: Official Journal of the
American Pain Society, 12(6), 677-686. doi:10.1016/j.jpain.2010.12.008
Varni, J. W., Seid, M., & Kurtin, P. S. (2001). PedsQL 4.0: reliability and validity of the
Pediatric Quality of Life Inventory version 4.0 generic core scales in healthy and
patient populations. Med Care, 39(8), 800-812.
48
Varni, J. W., Seid, M., & Rode, C. A. (1999). The PedsQL: measurement model for the
pediatric quality of life inventory. Med Care, 37(2), 126-139.
von Baeyer, C. L. (2009). Children's self-report of pain intensity: what we know, where
we are headed. Pain Res Manag, 14(1), 39-45. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/19262915
Walker, L. S., Garber, J., & Greene, J. W. (1991). Somatization symptoms in pediatric
abdominal pain patients: relation to chronicity of abdominal pain and parent
somatization. J Abnorm Child Psychol, 19(4), 379-394. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/1757708
Walker, L. S., & Greene, J. W. (1991). The functional disability inventory: measuring a
neglected dimension of child health status. J Pediatr Psychol, 16(1), 39-58.
Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/1826329
Ward, B. W., Schiller, J. S., & Goodman, R. A. (2014). Multiple chronic conditions
among US adults: a 2012 update. Prev Chronic Dis, 11, E62.
doi:10.5888/pcd11.130389
Wynne-Jones, G., Jones, G. T., Wiles, N. J., Silman, A. J., & Macfarlane, G. J. (2006).
Predicting new onset of widespread pain following a motor vehicle collision. J
Rheumatol, 33(5), 968-974. Retrieved from
http://www.ncbi.nlm.nih.gov/pubmed/16541476
Zernikow, B., Wager, J., Hechler, T., Hasan, C., Rohr, U., Dobe, M., . . . Blankenburg,
M. (2012). Characteristics of highly impaired children with severe chronic pain: a
5-year retrospective study on 2249 pediatric pain patients. BMC Pediatr, 12, 54.
doi:10.1186/1471-2431-12-54
49
CURRICULUM VITAE
Andrew John Becker
[email protected], 516-659-9810, Birth Year: 1992
Current Address: 30 Peterborough Street, Apartment 24, Boston, MA 02215
Permanent Address: 21 Noel Lane, Muttontown, NY 11753
EDUCATION
________________________________________________________________________
Boston University, Boston, MA
• School of Graduate Medical Sciences
• Masters of Science in Medical Sciences, May 2016
• Awarded Provost’s Scholarship recognizing excellent academic record and
promise of high scholarly achievement.
Boston College, Chestnut Hill, MA
• College of Arts and Sciences
• Bachelor of Science in Biochemistry, Pre-Medical Concentration, May 2014
• Studied Abroad in Florence, Italy in Summer 2012
WORK EXPERIENCE
________________________________________________________________________
Boston Children’s Hospital, Boston, MA
Research Intern
June 2015 – May 2016
• Examined the impact of precipitating events (unique incidents causing the onset
of chronic pain) on pediatric chronic pain recovery as my master’s thesis study.
• Led a comprehensive data extraction effort from 400 medical records that
involved inter-rater reliability coding with two fellow students.
• Recruited patients in the Sports Medicine Clinic for a neuroimaging study of
recovery and resistance in ankle sprain patients.
• Served as an ad-hoc reviewer on multiple manuscripts submitted for publication
to Journal of Pediatric Psychology, Pain, and Journal of Pain.
Eagle EMS of Boston College, Chestnut Hill, MA
Director of Professional Development / Supervisor
October 2010 – May 2014
• Provided 911 emergency medical response to the Boston College community and
surrounding areas through the operation of a Class V ambulance.
• Supervised teams of EMTs at large campus events to ensure proper patient care
and treatment.
• Presented an overview of goals and an outline of the future direction of the
organization to the Boston College Board of Trustees.
50
•
•
•
•
•
Oversaw the development of the organization and made decisions as a member of
the executive board.
Implemented a new application process as well as a 6-hour orientation session for
on-boarding new volunteers.
Solidified rank advancement process while helping modify rank structure.
Taught CPR to both students and faculty in monthly classes of 20 students lasting
four hours each.
Worked 500+ total hours over 4 years.
Long Island Thoracic Surgery, Lynbrook, NY
Research Assistant
June 2013 – August 2013
• Conducted retrospective chart review and statistical analysis of pneumothorax
occurrence and rates of relapse after surgery.
• Designed a project based on the findings of the research and had work presented
at a medical research symposium.
The Pool Company, Jericho, NY
Lifeguard
Summer 2009 – Summer 2012
• Provided lifeguarding coverage to five different pools in the area on a rotating
schedule for approximately 30 hours a week.
• Offered medical assistance to patrons, which required certifications beyond the
lifesaver certification.
• Managed the day-to-day operations of the individual pools including chemical
maintenance and pool sanitation.
VOLUNTEER EXPERIENCE
________________________________________________________________________
4 Boston, Chestnut Hill, MA
Volunteer
September 2011 – May 2014
• Volunteered at after-school care placement in Brighton, working with
approximately 50 elementary and middle school students on a weekly basis.
• Assisted at need children in subjects ranging from math and science to literature
and writing.
• Attended weekly reflections with the volunteer group of 15 students to develop a
deeper understanding of the social and economic challenges that affected our
students at the placement.
Student Admissions Program, Chestnut Hill, MA
Tour Guide
September 2013 – May 2014
• Conducted tours of Boston College and provide information about academics,
student life, and school history to prospective students and their families.
51
•
Interact with prospective students and their families, discussing my personal
college experience, answering questions and directing them towards resources.
CERTIFICATIONS
________________________________________________________________________
• Certified New York State Emergency Medical Technician, valid from September
2011 – September 2014
• AHA Basic Life Support for the Healthcare Provider, valid from June 2011 –
April 2015
• American Red Cross Lifeguard Certification, valid from June 2012 – June 2014
• Certified in the Incident Command System (100, 200, 700, 800)
ADDITIONAL SKILLS
________________________________________________________________________
Laboratory Experience
• One Year Organic Chemistry Lab, One Year General Chemistry Lab, One Year
Physics Lab, One Semester Analytical Chemistry Lab, One Semester Biology Lab
Microsoft Office
• Proficient in Microsoft Word, Excel, and PowerPoint
52