pii: sp-00769-14
http://dx.doi.org/10.5665/sleep.5170
DEVELOPMENT OF THE SLEEP PROBLEM ACCEPTANCE QUESTIONNAIRE
Measuring Acceptance of Sleep Difficulties: The Development of the Sleep
Problem Acceptance Questionnaire
Kristoffer Bothelius, MSc1; Susanna Jernelöv, PhD2; Mats Fredrikson, PhD1; Lance M. McCracken, PhD3; Viktor Kaldo, PhD2
Department of Psychology, Uppsala University, Uppsala, Sweden; 2Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden;
Health Psychology Section, Psychology Department, Institute of Psychiatry, King’s College London, London, UK
1
3
Study Objectives: Acceptance may be an important therapeutic process in sleep medicine, but valid psychometric instruments measuring
acceptance related to sleep difficulties are lacking. The purpose of this study was to develop a measure of acceptance in insomnia, and to
examine its factor structure as well as construct validity.
Design: In a cross-sectional design, a principal component analysis for item reduction was conducted on a first sample (A) and a confirmatory
factor analysis on a second sample (B). Construct validity was tested on a combined sample (C).
Setting: Questionnaire items were derived from a measure of acceptance in chronic pain, and data were gathered through screening or available
from pretreatment assessments in four insomnia treatment trials, administered online, via bibliotherapy and in primary care.
Participants: Adults with insomnia: 372 in sample A and 215 in sample B. Sample C (n = 820) included sample A and B with another 233
participants added.
Measures: Construct validity was assessed through relations with established acceptance and sleep scales.
Results: The principal component analysis presented a two-factor solution with eight items, explaining 65.9% of the total variance. The confirmatory
factor analysis supported the solution. Acceptance of sleep problems was more closely related to subjective symptoms and consequences of
insomnia than to diary description of sleep, or to acceptance of general private events.
Conclusions: The Sleep Problem Acceptance Questionnaire (SPAQ), containing the subscales “Activity Engagement” and “Willingness”, is a
valid tool to assess acceptance of insomnia.
Keywords: acceptance, experiential avoidance, insomnia, principal component analysis, psychometric evaluation, scale construction, Sleep
Problem Acceptance Questionnaire, willingness
Citation: Bothelius K, Jernelöv S, Fredrikson M, McCracken LM, Kaldo V. Measuring acceptance of sleep difficulties: the development of the
sleep problem acceptance questionnaire. SLEEP 2015;38(11):1815–1822.
INTRODUCTION
The concept of acceptance, the capacity to make an active
choice to be more open toward psychological experiences,1
has gained popularity and scientific support within behavioral
medicine.2 Acceptance has been most extensively studied in
relation to chronic pain,3,4 but also in diabetes,5 epilepsy,6,7
fatigue,8,9 smoking cessation,10,11 stuttering,12 and tinnitus,13,14
among other conditions. In behavioral medicine, acceptance
has been shown to be a key therapeutic process mediating the
effect of treatment methods on outcome, for example, in the
treatment of chronic pain15,16 and tinnitus.17 Identifying mediators of change may improve understanding of the nature of
health problems as well as enhance treatment effects.18 An area
where acceptance may also be relevant, but has not yet been
systematically investigated, is the area of insomnia or sleep
problems more generally.19–22
Acceptance is an important target for the therapeutic process in acceptance-based treatments. Acceptance and avoidance are counterparts, where “experiential avoidance” in
particular, is defined as attempts to control or limit contact
with distressing thoughts, feelings or other aversive internal
Submitted for publication December, 2014
Submitted in final revised form April, 2015
Accepted for publication May, 2015
Address correspondence to: Kristoffer Bothelius, MSc, Department of
Psychology, Uppsala University, Box 1225, 751 42 Uppsala, Sweden; Tel:
+46 70 398 12 13; Fax: +46 18 50 35 39; Email: kristoffer.bothelius@
psyk.uu.se
SLEEP, Vol. 38, No. 11, 2015
1815
experiences. Such avoidance reduces discomfort momentarily,
but may lead to long-term negative consequences.23 Preventing
experiential avoidance and facilitating experiential exposure,
including emotional exposure, seems to be one of the fundamental therapeutic components within a range of empirically
supported psychological treatments.24 Within an acceptancebased framework, the pathological process that drives insomnia could be described as beginning with the unpleasant
experience of being awake at night when one wants to be
sleeping, and being tired in the daytime when one wants to be
energetic.25 To avoid these experiences one may then adopt a
number of behavior patterns, such as spending excessive time
in bed trying to sleep, daytime napping, or other patterns that
constitute an irregular sleep-wake schedule.26 Unfortunately,
these behavior patterns interfere with homeostatic and circadian mechanisms, and can result in a conditioned arousal in
the bed and bedroom, which maintains sleep problems.27 Thus,
attempts to avoid disturbing experiences related to insomnia
can paradoxically feed the insomnia itself. An alternate behavior pattern would be to be open and accepting of the experiences of insomnia, which can certainly stop the struggling to
fall asleep, and possibly improve sleep. In order to address the
possible role of acceptance in relation to insomnia, a measure
of acceptance of sleep problems, such as insomnia, is needed.
General tools for measuring acceptance have been developed, for example, the Acceptance and Action QuestionnaireII.28 However, specific instruments are often more responsive
to change than generic instruments,29 and may better reflect
processes conceptualized in relation to a specific problem area.
In addition, it has been recommended that such instruments
The Sleep Problem Acceptance Questionnaire—Bothelius et al.
should be as short as possible, to minimize the burden on respondents.30–32 There is an example of a well-developed specifically focused instrument for measuring acceptance in chronic
pain, the 20-item Chronic Pain Acceptance Questionnaire
(CPAQ). It was originally based on a pool of 34 items.33 The
questionnaire is now extensively studied34 and shown to have
a two-factor structure assessing Activity Engagement (i.e., engaging in activities in the presence of pain) and Pain Willingness (i.e., refraining from attempts to control or reduce pain).35
The questionnaire has been adapted for use with tinnitus and
fatigue, and these adaptations have kept a similar two-factor
structure.36,37 For studying acceptance in insomnia, we aimed
to develop a new assessment instrument that we now refer to
as the Sleep Problem Acceptance Questionnaire (SPAQ). The
goal for this measure was to gain the ability to examine the
role of acceptance in relation to variables that reflect quality
of sleep, and also to determine whether acceptance could be
a treatment process variable. It was deemed desirable that the
questionnaire resemble similar acceptance questionnaires
used successfully in other behavioral medicine contexts.
The purpose of the current study was to investigate the
item content and factor structure, internal consistency, and
construct validity of the SPAQ. We predicted that the results
would reflect a two-factor structure found in subjects with
chronic pain, tinnitus, and fatigue as previously described,
and this is also in line with central constructs in acceptancebased theory: “willingness” (i.e., being fully in contact with
the present moment) and “committed action” (i.e., persisting
with or changing behavior in the pursuit of goals and values).1
Because acceptance of tinnitus mediates the effect of subjective tinnitus loudness on tinnitus distress,38 and acceptance
of chronic pain mediates the effect of pain severity on pain
interference,39 we predicted that acceptance of sleep problems would more closely relate to the subjective experience
of the disturbance than to descriptive aspects of sleep (such
as sleep onset latency and wake time after sleep onset). It was
hypothesized that the SPAQ should correlate positively with
other measures of acceptance and negatively with subjective
insomnia severity. It was also hypothesized that the SPAQ
would be negatively correlated with sleep onset latency and
wake time after sleep onset.
METHODS
Design
A principal component analysis (PCA) was conducted on a
first sample (A) to reduce the number of items, and this was
followed by a confirmatory factor analysis on a second sample
(B). Construct validity was assessed on a combined sample (C)
through regression analyses and correlations with established
measures of acceptance, insomnia, and other sleep related
factors.
Participants
Sample A consisted of screening assessments of 372 subjects applying for two studies of Internet-delivered cognitive
behavioral therapy for insomnia,40,41 72% women, mean age
42.0 (standard deviation [SD] = 15.0). Education level: compulsory school 5.5%, upper secondary school 26.6%, and
SLEEP, Vol. 38, No. 11, 2015
college/university 67.9%. The study protocol was approved
by the regional ethical review board in Stockholm (Diary No.
2009/1810-31/3), and is registered at ClinicalTrials.gov, registration ID: NCT01256099. Sample A+ includes these 372 participants, and an additional 233 who were screened after the
PCA had already been performed, resulting in 605 participants.
In sample B (total n = 215) subjects from two trials were
merged:
(I) Pretreatment assessments of 156 media recruited adults
with primary or comorbid insomnia participating in a bibliotherapy study,42 75% women, mean age 50.8 (SD = 11.8). Education level: compulsory school 4.5%, upper secondary school
29.5%, and college/university 65.9%. The study protocol was
approved by the regional ethical review board in Stockholm
(Diary No. 2008/23-31/4), and is registered at ClinicalTrials.
gov, registration ID: NCT01105052.
(II) Pretreatment assessment of 59 adults with primary or
comorbid insomnia participating in a randomized controlled
study of manual-guided cognitive behavior therapy for insomnia, delivered by ordinary primary care personnel in general medical practice,43 90% women, mean age 50.7 (SD = 11.7).
Education level: compulsory school 27.6%, upper secondary
school 51.7%, and college/university 20.7%. The study protocol was approved by the regional ethical review board in Uppsala (Diary No. 2008/080), and is registered at ClinicalTrials.
gov, registration ID: NCT01655797.
There was no statistically significant difference in age
between sample A (mean = 47.0, SD = 15.0) and sample B
(mean = 48.2, SD = 13.4), t(489.9) = 1.00, P = 0.32, nor sex,
χ2(1, n = 587) = 3.19, P = 0.07, but education level was higher in
sample A, χ2(2, n = 575) = 33.66, P < 0.001.
Subjects from sample A+ were merged with subjects in
sample B, forming sample C, composed of 820 subjects. All
subjects were screened for other common untreated sleep disorders in diagnostic interviews.
Measures
Instrument Development
The first two authors (KB and SJ) reviewed the 34 original
items behind the CPAQ, derived from Geiser,44 together with
a sleep expert (Jan-Erik Broman, PhD). Despite the fact that
all 34 items have not been used in any established version of
the CPAQ, they were considered to have potential relevance
for insomnia and were included in the initial principal components analysis. KB and SJ then translated all items to Swedish
and adapted them to insomnia. The items were backtranslated
into English and one of the authors (LM) then approved the
backtranslation from theoretical as well as semantic aspects.
The adaption was quite straightforward; most of the time by
simply exchanging “pain” with “sleeping problems”. This
formulation is in line with other measures of insomnia, for
example, the widely known Insomnia Severity Index.45 For
example, the item reading “although things have changed, I
am living a normal life despite my chronic pain” was changed
to “although things have changed, I am living a normal life
despite my sleeping problems.” Like the CPAQ, each item
is rated on a 0- to 6-response scale. For the SPAQ, 0 equals
“disagree” and 6 equals “completely agree.” Items for which a
1816
The Sleep Problem Acceptance Questionnaire—Bothelius et al.
high score implicates low acceptance are reversed in all statistical evaluations so that a high total score reflects a high
level of acceptance. Because our objective was a short questionnaire free from items with unclear wording, we wanted to
reduce the number of items in an initial principal components
analysis.
number of items per scale dimension,53,54 with at least four
items in each subscale.55 The item reduction was performed
stepwise, starting with excluding the items with the lowest
factor loading. Items with low standard deviations, double
loadings, or that were considered theoretically ambiguous
were also removed.
Additional Measures
Confirmatory Factor Analysis
Acceptance and Action Questionnaire-II: The Acceptance and Action Questionnaire-II (AAQ-II)28 is a seven-item
scale mostly focused on general psychological acceptance of
private events. All of the items are negatively keyed, so it is
sometimes referred to as a measure of experiential avoidance.
In the current study lower scores indicate higher acceptance.
Insomnia Severity Index: The Insomnia Severity Index
(ISI)45 is a widely used, reliable, and valid46 seven-item selfreport measure for insomnia, targeting subjective symptoms,
consequences of insomnia, and distress. A high total score indicates a high level of perceived sleep difficulties.
Dysfunctional Beliefs and Attitudes about Sleep Scale:
The Dysfunctional Beliefs and Attitudes about Sleep Scale
(DBAS)47 is a 30-item self-report questionnaire evaluating
sleep-disruptive cognitions. A higher score indicates more unhelpful cognitions.
Sleep-Related Behaviours Questionnaire: The 32-item
Sleep-Related Behaviours Questionnaire (SRBQ)48 is designed
to assess the use of safety behaviors in insomnia (i.e., strategies aiming to prevent a feared outcome, which may in fact
be contributing to the maintenance of the disorder). A higher
score indicates more safety behaviors.
Sleep Diary: Sleep diaries are routinely included in insomnia research. Despite an earlier lack of standardization,49
sleep diaries yield reliable quantification of sleep parameters
and are generally recommended for quantitative sleep assessment in insomnia research.50 Sleep diaries give information
about the night-to-night variability in sleep timing (bedtimes
and rise times), actual time slept (total sleep time, TST), how
many minutes it takes to fall asleep (sleep onset latency, SOL),
time spent awake during the night (wake time after sleep onset,
WASO), and percentage of time in bed spent asleep (sleep efficiency, SE).
Analyses
The 34 originally adapted items (called SPAQ-34) were included in screening or pretreatment measures in the three insomnia studies in Sweden previously described.
Principal Component Analysis
Item reduction was performed using an initial PCA with
oblique rotation (direct oblimin), starting with all 34 items
on sample A (n = 372). A wide range of recommendations
regarding sample size in factor analysis has been proposed.
Although there is a lack of agreement regarding rules of
thumb, Comrey’s guide suggesting a minimum of 300 subjects51 and Nunnally’s heuristic of a subject to item ratio of
10:152 are often cited. Both of these criteria were met. Because
we expected a two-factor solution, we restrained the number
of factors to two. We wanted a short questionnaire but still
followed the recommendations that measures have an equal
SLEEP, Vol. 38, No. 11, 2015
To confirm the factors suggested by the PCA, structural
equation modeling (SEM) was used to perform a confirmatory factor analysis (CFA) using sample B, n = 215. There is
no simple rule regarding minimum sample size in a CFA, but
having at least 200 subjects is advised.56 The AMOS software
package (version 22.0)57 was used for the CFA. To complement
the basic Chi-2 model fit test (testing if there is a difference
between the model and the data), which is known for being
very conservative except for small sample sizes, the following
model fit indices and cutoff values were used: root mean
square error of approximation (RMSEA < 0.08), comparative
fit index (CFI > 0.95), standardized root mean square residual
(SRMR < 0.09), and the Chi-2 value divided by the degrees of
freedom (Chi-2/df < 3).58–61
Construct Validity
Construct validity was assessed by examining the relations
with variables known to be theoretically linked with acceptance of insomnia. In these analyses, sample A+ was merged
with sample B forming sample C, amounting to 820 subjects.
To maximize power, missing data were excluded pairwise.
The Kolmogorov-Smirnov test showed data on SOL, WASO,
and SE derived from sleep diaries to be significantly different
from a normal distribution. This sleep diary data were therefore logarithmically transformed, which normalized distribution, before correlations were computed. To analyze the unique
contribution of the SPAQ on insomnia, a multiple regression
was performed, with ISI score as an outcome variable and the
SRBQ, the DBAS, and the SPAQ as predictors.
RESULTS
Principal Component Analysis
The principal component analysis was performed on sample
A. The reduction of items was performed in two steps and a
final solution with two four-item factors was presented. The
scree plot and the criterion of an eigenvalue above 1 supported
this solution, and the theoretical and statistical adequacy of
the items in each factor were inspected and found satisfactory. Thus, the solution presented in Table 1 was chosen. The
content of the two subscales was deemed to be well in line
with the corresponding subscales in the original CPAQ and
hence similar labeling of the subscales was used, i.e., “Activity
Engagement” and “Willingness”. The Kaiser–Meyer–Olkin
Measure of Sampling Adequacy was found to be 0.83, which
is considered good.62 The solution explained 65.9% of the total
variance among all eight items. The Cronbach α of the two
four-item subscales, 0.89 for Activity Engagement and 0.73 for
Willingness, were deemed satisfactory.63 The Cronbach α for
the scale as a whole was lower, 0.55. The correlation between
the two subscales was r = 0.22.
1817
The Sleep Problem Acceptance Questionnaire—Bothelius et al.
Table 1—Rotated factor loadings for the exploratory two-factor solution.
Item
1
2
3
4
5
6
7
8
Content summary
Although things have changed, I am living a normal life despite my sleeping problems.
I lead a full life even though I have sleeping problems.
My life is going well, even though I have sleeping problems.
Despite the sleeping problems, I am now sticking to a certain course in my life.
Keeping my sleeping problems under control takes first priority.
I need to concentrate on getting rid of my sleeping problems.
It’s important to keep on fighting these sleeping problems.
My thoughts and feelings about my sleeping problems must change before I can take important steps in my life.
Factor 1
0.88
0.87
0.84
0.84
−0.16
−0.061
0.17
−0.18
Factor 2
−0.056
−0.003
−0.076
−0.003
0.78
0.79
0.77
0.61
n = 372.
Table 2—Correlations between the Sleep Problem Acceptance Questionnaire (SPAQ) subscales (Activity Engagement and Willingness), the total SPAQ
score, and the Insomnia Severity Index (ISI), sleep onset latency (SOL), wake time after sleep onset (WASO), total sleep time (TST), sleep efficacy (SE),
the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS), and the Sleep-Related Behaviours Questionnaire (SRBQ).
Activity Engagement
Willingness
Total SPAQ-score
a
ISI
(n = 815)
−0.449 b
−0.450 b
−0.563 b
AAQ II
(n = 599)
−0.382 b
−0.193 b
−0.368 b
SOL
(n = 377)
−0.139 a
−0.078
−0.149 a
WASO
(n = 187)
−0.122
−0.245 a
−0.223 a
TST
(n = 377)
−0.039
0.080
0.082
SE
(n = 375)
0.087
0.050
−0.091
DBAS
(n = 195)
−0.397 b
−0.410 b
−0.514 b
SRBQ
(n = 195)
−0.534 b
−0.373 b
−0.594 b
P < 0.01. b P < 0.001.
was significant (χ2(19) = 45.8, P = 0.001), but this is very
common for large sample CFAs.64 Overall, the support for the
model was seen as sufficient considering that all other indicators were deemed strong or satisfactory, and we decided to let
the initial model also be the final model presented in Figure 1.
The Cronbach α for the whole measure was 0.59.
Figure 1—Structural equation model for the Confirmatory Factor
Analysis for the final version of the Sleep Problem Acceptance
Questionnaire.
Confirmatory Factor Analysis
The initial model with two factors was tested on sample
B in a confirmatory factor analysis. The SRMR (0.063), the
CFI (0.96), and the Chi-2/df (2.4) indicated adequate fit. The
RMSEA (0.081) was just above the threshold. The Chi-2 test
SLEEP, Vol. 38, No. 11, 2015
Construct Validity
For assessing construct validity, the newly developed SPAQ
was correlated against existing measures of insomnia and acceptance related constructs, see Table 2.
The SPAQ correlated negatively with the ISI and the AAQII. In the AAQ-II lower scores indicate higher acceptance so
this correlation is actually positive. The AAQ-II also correlated with the ISI, but to a lesser extent, r = 0.237, P < 0.001.
The SPAQ correlated negatively with WASO and SOL derived
from sleep diaries (but not with TST or SE), the DBAS, and
the SRBQ. The Activity Engagement subscale correlated negatively with SOL and the Willingness subscale correlated negatively with WASO. Both subscales correlated negatively with
the ISI, the AAQ-II, the DBAS, and the SRBQ. A multiple regression (forced entry in two steps) showed that in step 1, both
the SRBQ and DBAS significantly predicted ISI score and together they predicted 17% of the variance. When the SPAQ
was added in the second step, the total predicted variance increased significantly (P < 0.001) by another 15% and only the
SPAQ remained a significant predictor (Table 3). We therefore
re-performed these analyses, but separately adding the two
subscales of SPAQ to the SRBQ and the DBAS. When “Willingness” was added in the second step (B = −0.20, P = 0.001),
the SRBQ remained significant (B = 0.05, P = 0.03), but not the
DBAS. When the “Activity Engagement” subscale was added
1818
The Sleep Problem Acceptance Questionnaire—Bothelius et al.
instead in step 2 (B = −0.24, P < 0.001) the DBAS was still
significant (B = 0.02, P = 0.02), but not the SRBQ.
In sample A+ mean value for the total SPAQ score was
20.23 (SD = 8.37), for the Activity Engagement subscale
11.97 (SD = 5.77), and for the Willingness subscale 8.25
(SD = 4.66). In the bibliotherapy study mean value for the
total SPAQ was 17.16 (SD = 8.09), for the Activity Engagement subscale 9.26 (SD = 5.46), and for the Willingness subscale 7.90 (SD = 4.96). In the primary care study mean value
for the total SPAQ was 18.47 (SD = 9.11), for the Activity Engagement subscale 12.03 (SD = 5.70), and for the Willingness
subscale 6.44 (SD = 5.21).
DISCUSSION
The aim was to develop and validate a brief measure of
acceptance of sleep problems. This resulted in the SPAQ, an
eight-item questionnaire with two factors, Willingness and
Activity Engagement. To our knowledge, this is the first specific measure of acceptance in insomnia. This structure is in
agreement with two-factor solutions found for similar acceptance questionnaires used in chronic pain, tinnitus, and fatigue,
and our labeling of the subscales as Activity Engagement and
Willingness was in line with these other measures.
An analysis of construct validity shows that the SPAQ has a
strong negative correlation with the ISI, but only a weak negative correlation with SOL and WASO, and no correlation with
SE or TST. This is somewhat in line with what was predicted;
low acceptance of insomnia is more closely related to subjective effect of severe sleeping problems, than to more descriptive aspects of the sleep (e.g., long time awake during the night
and short sleep length). The negative correlation between the
SPAQ and the negatively keyed AAQ-II (in fact a positive correlation) was medium sized, whereas the correlation between
the AAQ-II and the ISI was small. The insomnia-specific
measure of acceptance, SPAQ, hence seems to correlate fairly
well to the more general acceptance questionnaire AAQII, while at the same time correlating more closely with the
subjective symptoms and consequences of insomnia than the
AAQ-II manages to do. A negative correlation with the AAQII is expected because this measure is theoretically reversed
and reflects avoidance. The SPAQ correlates highly negatively
with both the DBAS and the SRBQ, indicating that lower acceptance of insomnia is closely related to more sleep-disruptive beliefs, attitudes, and safety behaviors. As shown in the
multiple regression analysis, the SPAQ reflects a unique concept that may be of importance for understanding perceived
insomnia severity and for guiding psychological treatment
for insomnia.
Activity Engagement means persistence with normal activities, even when sleep is perceived as not being satisfying,
whereas Willingness reflects refraining from attempts to fight
sleep problems and control sleep. These scales mirror the
central theoretical construct in acceptance-based therapies:
“psychological flexibility.” This construct, in turn, reflects
the ability to experience the current moment without trying
to change it and to engage in personally important activities;
again, both when it is easy to do this but particularly when
one encounters potential barriers such as unwanted or discouraging thoughts and feelings.1 In insomnia this could be
SLEEP, Vol. 38, No. 11, 2015
Table 3—Multiple regression with the Insomnia Severity Index as
outcome variable, the Dysfunctional Beliefs and Attitudes about Sleep
and the Sleep-Related Behaviours Questionnaire as predictors in
step 1, and the Sleep Problem Acceptance Questionnaire added in
step 2.
Step 1
Constant
DBAS
SRBQ
B
SE B
β
9.21
0.03
0.06
1.42
0.01
0.02
0.22a
0.23a
Step 2
Constant
DBAS
SRBQ
SPAQ
20.37
0.01
0.00
−0.22
2.13
0.01
0.02
0.03
0.11 (ns)
0.00 (ns)
−0.50b
R 2 = 0.17 for Step 1, ΔR 2 = 0.15 for Step 2 (P < 0.001). aP < 0.01.
b
P < 0.001. DBAS, Dysfunctional Beliefs and Attitudes about Sleep;
ns, not significant; SRBQ, Sleep-Related Behaviours Questionnaire;
SPAQ, Sleep Problem Acceptance Questionnaire.
translated to willingness to experience nonoptimal sleep, and
to direct energy toward personally important goals despite
resistance, instead of fighting or trying to control insomnia.
An instrument to assess acceptance, and it subcomponents, in
insomnia is necessary to examine the relations between acceptance, suffering, and treatment outcome. The results suggest that these two subscales represent a whole process and
both ought to be included when one is interested in acceptance in insomnia.
Acceptance is an active choice. In other behavioral medicine disciplines there is accumulating evidence that pursuing
valued activities may be a more successful approach to chronic
diseases, as opposed to fighting against or trying to avoid unpleasant symptoms.2 Although fighting or avoiding unwanted
experiences might result in temporary relief from these symptoms, this form of experiential avoidance may result in increased interference with life in the long run. In chronic pain
research there are data showing that low acceptance is correlated with both high psychological distress and high physical
disability,65–67 and in chronic fatigue low acceptance has been
shown to relate to high psychological distress9 and to predict
low physical functioning.8 The role of acceptance in insomnia
could be, as with diabetes,5 both an important mediator of
change, and a desired outcome following treatment. From a
purely theoretical standpoint however, acceptance is never the
ultimate goal—only a way to approach life in tune with one’s
values.1 Likewise, symptom reduction is not an end goal of
acceptance-based treatment, but such treatment has nonetheless been shown to reduce the number of epileptic seizures6,7
and reduce overall frequency of stuttering,12 showing that acceptance is not merely an inert response to symptoms, or passive resignation. One possible difference between acceptance
in insomnia and acceptance in, for example, chronic pain and
tinnitus is in the willingness factor. In tinnitus and chronic
pain this factor seems to be characterized by control and avoidance, whereas in insomnia there is more of control and fight.
One item that is unique for the SPAQ is: “It’s important to keep
1819
The Sleep Problem Acceptance Questionnaire—Bothelius et al.
on fighting these sleeping problems,” and in contrast with the
CPAQ and the Tinnitus Acceptance Questionnaire (TAQ)36
items do not include conventional avoidance behavior patterns. One could speculate there might be different qualities
in the acceptance behaviors that are most typical for different
underlying conditions. For example, passive avoidance and
withdrawal may relate more to depressive behavior problems
in chronic pain and tinnitus, and require greater behavioral
activation as a therapeutic response,68 whereas a more actionoriented fighting style of avoidance in insomnia may lend itself
to problems with states of hyperarousal69 and a dysregulated
stress system,70 thus requiring different therapeutic methods
that reduce the effect of thoughts and feelings on behavior.
It is worth emphasizing the potential value of an assessment
instrument that can provide reliable and valid data regarding
acceptance of insomnia. Currently, in most areas of cognitive
behavioral therapy, there is an increased interest in therapeutic
process, or active mechanisms of treatment effect. Aspects of
psychological flexibility, such as acceptance, appear to hold
great potential as process variables that can help us to better
select, target, and optimize methods for addressing problems
such as sleep disturbance and insomnia.4
The study has some limitations that deserve mention. The
four-plus-four-item version that the authors advocate is based
on statistical considerations, as well as a theoretical discussion
of balancing two important constructs. Because the questionnaire contains two different factors, the Cronbach α for the
whole scale is low, and it is important to consider the subscales
separately when interpreting the scores.71 The study did not assess the test-retest reliability of the measure or its sensitivity to
change, and it did not produce clinically relevant cut-off scores
that allowed for individual scores to be classified as high or
low. Even if the SPAQ shows significant correlations with other
insomnia specific measures, these correlations cannot support
conclusions regarding causality, and it is possible that the relations are bidirectional. Finally, all subjects had a verified insomnia diagnosis and were seeking treatment. It is possible
that a population not seeking treatment or with subthreshold
insomnia may have responded differently. A merit of the study
is that the factor structure is validated on a separate sample.
Future studies might assess the prognostic value of SPAQ
scores for different insomnia treatments and explore whether
acceptance of sleep problems can explain some of the differences between descriptive sleep measures and subjective insomnia severity, in line with how tinnitus-specific acceptance
partially mediates the relation between subjective tinnitus
loudness and tinnitus distress,38 and how pain-specific acceptance partially mediates the relation between pain severity and
pain interference.39
To conclude, the SPAQ seems to be a theoretically adequate
and statistically sound measure of acceptance in people with
insomnia. In future use of the SPAQ, one should consider
not only the total score, but also the two subscales. Although
insomnia was meant to be the main target of this questionnaire, and represents the primary problem within the samples for which the measure has been developed, the uses of
generic sleep concepts in the questionnaire enable studies of
acceptance in populations with sleep disturbances other than
insomnia.
SLEEP, Vol. 38, No. 11, 2015
ACKNOWLEDGMENTS
The authors thank Ingrid Andrén, Kerstin Blom, Martin
Kraepelien, Kicki Kyhle, Brjánn Ljótsson, Sara Rydh, and Sofi
Sjöholm-Jenssen for help with data collection, Sandra Bates
for help with the back translation, Sheri Fox for proofreading,
and Jan-Erik Broman for help with the development of the
SPAQ and valuable comments on the manuscript.
DISCLOSURE STATEMENT
This was not an industry supported study. Dr. Jernelöv is the
author of a commercially available self-help book used in three
of the randomized trials from which data were collected. The
other authors have indicated no financial conflicts of interest.
The work was performed at the Department of Psychology,
Uppsala University, Uppsala, and the Department of Clinical
Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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APPENDIX
Sleep Problem Acceptance Questionnaire
Directions: Below you will find a list of statements. Please rate how much you agree with each statement by marking one alternative. Use the rating scale
below to make your choices.
0
1
2
3
4
5
6
Disagree
Almost completely
disagree
Slightly agree
Partly agree
Moderately agree
Almost completely
agree
Completely agree
1.Although things have changed, I am living a normal life despite my sleeping problems.
2.I lead a full life even though I have sleeping problems.
3.My life is going well, even though I have sleeping problems.
4.Despite the sleeping problems, I am now sticking to a certain course in my life.
5.Keeping my sleeping problems under control takes first priority.
6.I need to concentrate on getting rid of my sleeping problems.
7.It’s important to keep on fighting these sleeping problems.
8.My thoughts and feelings about my sleeping problems must change before I can take important steps in my life.
Scoring
Activities Engagement: Sum items 1, 2, 3, 4. Willingness: Reverse score items 5, 6, 7, 8, and sum. Total: Activity Engagement + Willingness.
High scores equals high level of acceptance.
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The Sleep Problem Acceptance Questionnaire—Bothelius et al.