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International Journal of Nursing Studies 41 (2004) 833–841
The impact of a stage-matched intervention to promote
exercise behavior in participants with type 2 diabetes$
Chun-Ja Kima,*, Ae-Ran Hwangb, Ji-Soo Yooc
a
University of Alabama-Birmingham School of Nursing, G010B NB, 1530 3rd Ave. S., Birmingham, AL 35294-1210, USA
Department of Hospice Care, Yonsei University Medical Center, 134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-752, South Korea
c
Department of Basic Nursing Science, College of Nursing, Yonsei University, 134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-752,
South Korea
b
Received 30 October 2003; received in revised form 11 March 2004; accepted 16 March 2004
Abstract
This study was designed to develop and evaluate a stage-matched intervention (SMI) in Korean participants with
type 2 Diabetes. The SMI was based on main constructs derived from the Transtheoretical Model match to the
individual’s stages of readiness for exercise behavior. The SMI was developed according to the results of the content
validity tested by an expert group (n ¼ 9). A control group pre- and post-test design was used for evaluating the impact
of the SMI: the intervention group (n ¼ 22) participated in the SMI for 3 months, while the control group (n ¼ 23)
received usual educational advice. The intervention group, compared to the control group, showed significant
improvements in stages of change for exercise behavior (p o 0.001), physical activity levels (p o 0.001), and reductions
in FBS (p o 0.05) and HbA1c (p o 0.05). This study yielded evidence for the beneficial impact of the SMI in
participants with type 2 Diabetes.
r 2004 Elsevier Ltd. All rights reserved.
Keywords: Exercise behavior; Psychological theory; type 2 Diabetes
1. Introduction
Diabetes mellitus (DM) has become an increasingly
serious health problem, and the prevalence of diabetes in
South Korea (SK), among people older than 20 years of
age, was about 10.0% in 1999 (KIHSA, 2001). Three
major therapies for DM control and management are
diet, exercise, and medication. While specific guidelines
for diet and pharmacological management in diabetes
$
This study was partly supported by the Post-doctoral
Fellowship Program of Korea Science & Engineering Foundation (KOSEF) to Dr. C.-J. Kim.
*Corresponding author. Tel.: +1-205-934-7589; fax: +1205-975-6194.
E-mail addresses: [email protected] (C.-J. Kim), dabbie17@
hanmail.net (A.-R. Hwang), [email protected]
(J.-S. Yoo).
have been developed (KDA, 1999), such guidelines have
yet to be developed for exercise in SK (KACEP, 2000).
Most of the previous studies on exercise for patients
with DM in SK have focused on the physiological
outcomes (Jun, 2000). It has been well known that
regular exercise is the most helpful intervention for
improving blood glucose (i.e. fasting blood sugar and
glycosylated hemoglobin, etc.) and lipid profiles (i.e.
total cholesterol, triglyceride, high density level cholesterol, etc.) (Hwang et al., 2000, 2001; Jun, 1994; Kim,
1989, 1998; Lee, 1990; Na et al., 1993), improving
cardiopulmonary function (i.e. maximum oxygen uptake, etc.) (Hwang et al., 2000, 2001; Jun, 1994; Kim,
1998; Na et al., 1993), and improving fat composition
(i.e. lean body mass, fat body mass, waist to hip ratio,
etc.) (Hwang et al., 2000, 2001).
Despite the many benefits of exercise, the findings
from numerous epidemiological and clinical studies
reported that over half of those who had participated
0020-7489/$ - see front matter r 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.ijnurstu.2004.03.009
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C.-J. Kim et al. / International Journal of Nursing Studies 41 (2004) 833–841
in exercise program discontinued participation within
3–6 months (Dishman, 1991; Hwang, 1999; Lee, 1997).
Similarly, Hwang et al. (2001) have reported that 35%
of Korean patients with type 2 DM were still doing the
exercises 7 months after the start of a 12-week exercise
program. In fact, the benefits of exercise do not persist
without continued, regular participation. Therefore,
researchers are faced with the dual challenges of
increasing exercise adoption among sedentary individuals and developing effective approaches to assist
individuals in maintaining their exercise habits once
these are established (Bock et al., 2001).
Exercise researchers have recommended the use of the
Transtheoretical Model (TTM) which includes strategies
to assist individuals in making transitions across the
various stages of change (SOC) in exercise behavior
(Prochaska and Marcus, 1994). A unique strength of
applying the TTM to the study of exercise behavior is
the dynamic nature of moving from the early stages of
behavior adoption to the maintenance stage of the
behavior. The main constructs of the TTM include
motivational readiness for SOC, self-efficacy (SE),
decisional balance (DB), and a number of cognitive
and behavioral processes of change (POC) (Prochaska
and Marcus, 1994; see Table 1).
The TTM uses the SOC to understand the dynamic
process through which an individual transits when
making an intentional exercise behavioral change. The
stages identified for exercise behavior are pre-contemplation (PC; no intention of exercise), contemplation
(C; intending to exercise within the next 6 months),
preparation (P; exercising some, but not regularly),
action (A; exercising regularly for less than 6 months),
and maintenance (M; exercising regularly for 6 months
or more). The TTM posits that stage transition results
via stage-specific cognitive and behavioral process. The
cognitive processes used most in the early stages include
consciousness raising, dramatic relief, environmental
reevaluation, self-reevaluation, and social liberation.
The behavioral processes, more frequently used during
the later stages, are counter conditioning, helping
relationships, reinforcing management, self-liberation,
and stimulus control. Further, each of the stages is
characterized by changes in DB, the balance between
benefits (pros) and costs (cons) associated with engaging
in a behavior. DB is thought to be important for
progression within the earlier stages (PC to P). SE, the
perceived ability that one can engage in a behavior
under given circumstances, is also incorporated into the
TTM and is thought to be more important in the later
stages (P to M) (Prochaska and Marcus, 1994).
The stage-matched intervention (SMI) is based on
those main constructs derived from the TTM match
intervention to the individual’s stages of readiness for
exercise behavior. The TTM is based on the idea that
people differ in their levels of readiness to change their
behavior. Therefore, the SMI uses differing strategies
and techniques to bring about exercise behavior change.
Additionally, the SMI’s goals differ based on the
individual’s level of motivation for change. The SMI
highlights the need to assess physical and psychological
issues when designing interventions and helps in the
selection of strategies for exercise behavior change that
may be most useful for people with different levels of
motivation to change (Marcus and Forsyth, 2003).
Both longitudinal and cross-sectional studies have
shown that the degree to which individuals endorse these
constructs varies systematically with the current participation in exercise behavior (Bock et al., 2001; Marcus
et al., 1998). A SMI program is the most effective
Table 1
Main strategies as they apply to exercise behavior
Main strategies
Cognitive processes of change
Consciousness raising
Dramatic relief
Environmental reevaluation
Self-reevaluation
Social liberation
Behavioral processes of change
Counter-conditioning
Helping relationships
Reinforcement management
Self-liberation
Stimulus control
Self-efficacy
Decisional balance
Pros
Cons
Definition
An individual undertaking to find out more about exercise behavior
Caring about consequences of inactivity or non-exercise.
Understanding how inactivity affects the physical/social environments
Seeing oneself as an active person
Awareness and acceptance of social changes encouraging active lifestyles
Substituting alternatives for inactivity or non-exercise
Seeking out social support to help adopt and maintain exercise
Using rewards to encourage or maintain behavior changes
Choosing and making commitment to change, believing in one’s ability to change behavior
Avoiding or controlling stimuli and other causes that support inactivity or non-exercise
Confidence in being able to be active in a variety of situations
Benefits of adopting or maintaining exercise behavior
Barriers or costs in adopting or maintaining exercise behavior
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program because it can meet all of the individuals’
needs based on their stages (Marcus et al., 1998).
Whereas other programs are appropriate only to
people who already have an intention to do an exercise,
the stage-based intervention programs can be
applied to all of the population, including people in
the pre-contemplation and contemplation stages (Marcus and Simkin, 1993). Further, Ruggiero (2000) has
reported that the TTM also provides a useful framework
for helping people with diabetes change behavior.
However, most previous studies have been conducted
on healthy populations in community settings. Little
research has specifically examined patients with type 2
DM in SK.
The purpose of this study is to develop the SMI
using content validity with an expert group and
evaluate the impact of the SMI in type 2 diabetic
Korean participants. The SMI will promote the adoption and maintenance of exercise behavior among
type 2 diabetic populations. For evaluation of the
impact of the SMI, we hypothesize that an intervention
group who participated in the SMI, compared to a
control group, will show a more advanced SOC, higher
physical activity levels, and greater reductions in fasting
blood sugar (FBS) and glycosylated hemoglobin
(HbA1c).
2. Methods
2.1. Development of the SMI
The TTM was used to guide the SMI design. In order
to determine the appropriate content for the SMI, a
questionnaire package was distributed to the type 2
diabetic Korean participants (n ¼ 100) to gain data on
the following: (a) distribution of SOC including their
level of knowledge, attitude, intention and compliance
to exercise behavior; (b) which strategies such as POC,
SE, and DE are the most used corresponding to the each
stage; (c) any specific difficulties and coping strategies in
adopting and maintaining exercise behavior. The content for the SMI was determined by the results of the
questionnaire package and remarks in the literature
(Kim, 2002a).
For content validity an expert review and a panel
discussion were conducted with 9 experts in SK. The
expert group consisted of two medical doctors specializing in diabetes and preventive medicine, two nursing
faculty also specializing in diabetic care, one diabetic
education nurse, two exercise prescription specialists
who are knowledgeable about diabetes, one health promotion faculty member who is knowledgeable about the
TTM, and one exercise program specialist. The experts
were asked to review and score 14 components of the
SMI for content validity: (a) theoretical background
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and goal, (b) definition, (c) methods, (d) setting, (e)
assessment tool for the current SOC and physical
readiness, (f) five SMI packages, (g) main theme, (h)
intervention goal and objectives, (i) main resources and
strategies, (j) frequent needs or questions, (k) main
counsel or answer guidelines, (l) glossary, (m) examples
of exercise behavior, and (n) format of algorithm. They
were asked to rate the importance of each component
using a 4-point rating scale ranging from 1 (not at all
important) to 4 (very important). The content validity
index (CVI) of each component was calculated based on
the experts’ ratings. The CVI score was computed by
summing the percentage agreement scores of all
components that were given a rating of ‘‘3’’ or ‘‘4’’ by
the experts. Components were considered adequate if
there was more than 79% agreement (Lynn, 1986). The
mean agreement of the SMI was 90.0% (range: 83.3–
97.2%). Finally, the SMI was revised by using the results
of the content validity and then completed by the
researcher (Kim, 2002b). The final version of SMI
protocol is briefly summarized in Fig. 1.
2.2. Evaluation of the impact of the SMI
2.2.1. Research design
A control group pre- and post-test design was used for
evaluation of the SMI. The participants were assigned to
the two groups by group matching with current SOC.
The independent variable was the SMI and the
dependent variables were SOC for exercise behavior,
physical activity levels, FBS, and HbA1c. The intervention group participated in the SMI during 3 months,
while the control group received usual educational
advice. The dependent variables were measured at
baseline and immediately following completion of the
intervention.
2.2.2. Participants and setting
Forty-five participants were recruited from an
Outpatient Diabetic Center at a large University
Hospital in SK, of whom 22 were in the intervention
group and 23 in the control group. The study had
ethical approval by the Institutional Review Board for
human subject protection. Physicians were asked to
review the medical record and condition of each
patient and to then refer the eligible patient who met
the following inclusion criteria: (a) less than 240 mg/dl of
FBS and/or less than 10.0% of HbA1c, (b) less than
20 years of DM history with no chronic complications
such as severe retinopathy, nephropathy, or neuropathy,
(c) no evidence of heart disease, musculoskeletal
disorders, or other disabling diseases that could restrict
the exercise behavior training, and (d) no insulin. The
researcher met the referred patients and obtained
informed consent by those who agreed to participate
in the study.
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Assessment
C.-J. Kim et al. / International Journal of Nursing Studies 41 (2004) 833–841
Goal
(Pre-contemplation stage)
• Identify any specific reasons not considering physical activity/exercise
• Knowing the specific health benefits of physical activity/exercise
• Thinking about ordinary physical activity in lifestyle
• Thinking about risks of sedentary lifestyle
Go for it
(Contemplation
stage)
• Considering the specific benefits and barriers of physical activity/exercise
• Setting short- and long-term goal and increasing lifestyle physical activities
• Developing a list of solutions to overcome specific barriers
• Believe in one’s ability to become a physically active individual someday
Stages of
readiness for
exercise
behavior
with PAR-Q*
Get ready it
(Preparation
stage)
• Setting individualized exercise prescription and specific aims of exercise training
• Learning how to plan to cope with an emergency situation in order to exercise
• Learning how to keep and monitor daily exercise log
• Having confidence in being able to exercise in a variety of situations
Keep it going
(Action stage)
• Re-establishing specific aims or reasons for exercising for helping diabetes
• Evaluating current exercise pattern and adjust properly to exercise training
• Increasing confidence in keeping exercise, overcoming barriers and preventing boredom
• Using rewards, supports, and contracts from self and/or others
Make it a habit
(Maintenance
stage)
• Reminding specific aims or reasons for doing regular exercise
• Evaluating current exercise pattern and planning ahead for difficult situations
• Keeping confidence, avoiding injury, and using rewards, supports, and contracts
Evaluation
Feedback: Go to re-assessment and move into the appropriate next stage
Think about it
The SMI: Main Strategies & Guidelines
• Restarting exercise within 1-2 weeks if relapse occurs
Fig. 1. The SMI protocol. PAR-Q denotes physical activity readiness questionnaire, CDC, USA.
2.2.3. The SMI protocol
The SMI was designed for health providers in
outpatient practice to promote the adoption and
maintenance of exercise behavior. The 12-week SMI
consisted of three components: (a) the stage-matched
counseling strategies based on main constructs derived
from the TTM such as POC, SE, and DB; (b) exercise
behavior training based on an individualized exercise
prescription obtained from graded exercise test (GXT)
the participants had performed; and (c) telephone
counseling.
2.2.3.1. Stage-matched counseling strategies (SMCS).
The SMCS protocols consisted of preplanned exercise
counseling strategies that were individually tailored by
targeting remarks of the questionnaire package based on
the Korean diabetic participant’s use of constructs from
the TTM (Kim, 2002a). The SMCS were provided
individually to each participant during a 60- to 90-min
initial counseling session with the researcher. The SMCS
was made up of five packages corresponding to the
participant’s current SOC (Kim, 2000b) and main
strategies as they applied to exercise behavior: (a) for
the PC package consisted of consciousness raising, DB,
and SE; (b) for the C package consisted of dramatic
relief, environmental reevaluation, self-reevaluation,
DB, and SE; (c) for the P package consisted of selfliberation, reinforcement management, DB, and SE; (d)
for the A package consisted of reinforcement management, helping relationships, counter-conditioning, stimulus control, and SE; and (e) for the M package
consisted of self-liberation, reinforcement management,
stimulus control, helping relationships, counter-conditioning, and SE (see Fig. 1).
2.2.3.2. Exercise behavior training. All participants
were assessed for their present stage of readiness for
exercise through the assessment tool for SOC. Then a
GXT on a model Oxycon Delta treadmill (JAEGER
GmbH, Wuerzburg, Germany) and an individualized
exercise behavior prescription were performed: (a)
Mode—brisk walking, stair climbing, cycling, climbing,
jogging or running on treadmill, and household, leisure
or job physical activity; (b) Frequency—3–5 days a
week; (c) Duration—30 min of aerobic exercise and
5 min for warm-up or cool-down; (d) Intensity—low to
moderate intensity, 40–75% VO2max based on results of
the GXT and physical condition of each participant; and
(e) Progression—To adjust for cardiovascular and
muscular adaptations from training, the program leader
reassessed and adjusted participant’s heart rate responses at least for the first 2–3 weeks. Participants in
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early stages (PC to P) performed the moderate activity
described by the recent CDC/ACSM recommendation
on physical activity (Pate et al., 1995). Multiple episodes
of moderate intensity physical activity such as brisk
walking can be accumulated in sessions of at least 10 min
to reach the total of 30 min a day. The participants
maintained weekly exercise behavioral logs, indicating
the frequency, duration, and kcal for energy expenditure
by pedometer. Adherence rate during the SMI was
87.5%.
2.2.3.3. Telephone counseling. Telephone counseling
was provided for 10–30 min twice a week by the
researcher who encouraged their confidence in being
able to exercise in a variety of situations. Problems and
concerns in performing the SMI were discussed. If the
participant had any problems or concerns, they were
informed to call the researcher at any time, and then
they searched together for the specific and practical
problem solving skills and coping strategies.
2.2.4. Measurement
Demographic variables including age, gender and
duration of DM were assessed by the review of medical
records upon entry into the study. Repeated measures
included SOC for exercise behavior, physical activity
levels, FBS, and HbA1c.
SOC were assessed using the stages of readiness for
exercise behavior scale (Marcus and Simkin, 1993). The
scale requires the subject to choose which of the five
statements describes best his or her current exercise
pattern and performance. Each of the statements
corresponds to one of the SOC from pre-contemplation
to maintenance: ‘‘I currently do not engage in physical
exercise and I am not thinking about starting’’ (PC); ‘‘I
currently do not engage in physical exercise but I am
thinking about starting’’ (C); ‘‘I currently engage in
some physical exercise but not regularly’’ (P); ‘‘I
currently engage in regular physical exercise but I have
only begun to do so within the last 6 months’’ (A); ‘‘I
currently engage in regular physical exercise and I have
done so for longer than 6 months’’ (M). Each stage was
assigned a numeric value on a five-point continuous
scale, with 1 representing the lowest level of readiness to
change (PC) and 5 representing the highest readiness to
change (M). This instrument has been shown to have
adequate test-retest reliability (Kappa index=0.78)
(Marcus et al., 1992). It has also been shown to have
good concurrent validity with the standard intervieweradministered 7-day physical activity questionnaire (Sallis et al., 1985), and construct validity of SOC for
exercise behavior and physical activity (Cardinal, 1997;
Schumann et al., 2002).
Physical activity levels were assessed using a selfreport instrument adapted from the 7-day physical
activity questionnaire (Sallis et al., 1985). The activity
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assessment questionnaire required the participant to
recall their exercise starting with the same day 7 days
ago. Time markers such as morning and lunchtime were
used to increase the accuracy of recall. For each activity
listed, the subject completed a section asking how often
(frequency), how long (duration) and how intense
(intensity) their physical activity bouts were. A physical
activity energy score was calculated from time spent in
various activities and standard metabolic equivalents
(MET) for those types of activities. One MET is
considered to be equal to 3.5 ml/kg/min (Sallis et al.,
1985).
FBS was measured by BIOSEN 5030 autoCal, (EKFdiagnostic GmbH, Magdeburg, Germany; accuracy,
failure o1.5% @ 12 mmol/l) and HbA1c, NycoCard
READER II, (Axis-Shield PoC., Oslo, Norway; accuracy, failureo5%).
2.3. Statistical analyses
The SPSS statistical software package (Version 11.0
for Windows, SPSS, Chicago, IL, USA) was used to
analyze the data. Descriptive statistics were used to
characterize the sample and variables of the study. Chisquare test for categorical variables and t-test or Mann–
Whitney U test for continuous variables were used to
test differences between the intervention group and the
control group, and paired t-tests were used to analyze
differences between pre-intervention and post-intervention values.
3. Results
3.1. Participants’ characteristics
Demographic characteristics and outcome measurements at baseline for participants are detailed in Table 2
and briefly summarized here. The mean age of the
participants was 53.29 years (SD 10.21), and most
participants were male (62.2%). The mean duration of
diabetes was 7.39 years (SD 6.80). At baseline the two
groups did not differ on any outcome measurements,
including SOC for exercise behavior, physical activity
levels, FBS, and HbA1c.
3.2. Impact of the SMI
Significant increases in overall SOC (t ¼ 3:53;
po0:001) and physical activity levels (t ¼ 4:78;
po0:001) in the two groups are shown in Table 3. The
intervention group advanced (+0.95 score), whereas the
control group did not change significantly. The percentage of participants who progressed from baseline in the
intervention group was 77.4%, while in the control
group it was only 4.3%. Significant differences in the
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Table 2
Demographic characteristics at baseline
Mean (SD)
Gender (male/female)
Age (years)
Duration of diabetes (years)
Stages of change (score)
Physical activity levels (METs x h/week)
FBS (mg/dl)
HbA1c (%)
Intervention group (n ¼ 22)
Control (n ¼ 23)
w2 or t
p
13(59.1%)/9(40.9%)
53.82 (7.42)
7.45 (7.32)
3.41 (1.33)
14.65 (5.11)
156.32 (39.11)
7.84 (1.63)
15(65.2%)/8(34.8%)
52.78 (12.46)
7.32 (6.37)
3.22 (1.35)
14.48 (4.76)
153.74 (37.94)
7.78 (1.72)
0.18
3.54
4.60
0.48
0.11
0.23
0.12
0.76
0.47
0.47
0.63
0.91
0.82
0.91
METs denotes metabolic equivalents, 1MET=3.5 ml/kg/min. FBS denotes fasting blood sugar. HbA1c denotes glycosylated
hemoglobin. w2-value is only gender difference between the two groups.
Table 3
Group differences in outcome measurements
Mean (SD)
Stages of change (score)
Physical activity levels
(METs x h/week)
FBS (mg/dl)
HbA1c (%)
Baseline
Post-test
Baseline
Post-test
Baseline
Post-test
Baseline
Post-test
Intervention group (n ¼ 22)
Control group (n ¼ 23)
t
p
3.41 (1.33)
4.36 (0.66)
14.65 (5.11)
29.43 (11.1)
156.32 (39.11)
139.14 (30.15)
7.84 (1.63)
6.96 (1.19)
3.22 (1.35)
3.22 (1.38)
14.48 (4.76)
14.87 (7.72)
153.74 (37.94)
164.35 (43.22)
7.78 (1.72)
8.19 (2.07)
3.53
0.001
4.78
0.000
2.26
0.03
2.44
0.02
METs denotes metabolic equivalents, 1MET=3.5 ml/kg/min. FBS denotes fasting blood sugar. HbA1c denotes glycosylated
hemoglobin.
contemplation (Z ¼ 2:00; po0:05), preparation (Z ¼
2:52; pp0:01), and action stages (Z ¼ 2:43; po0:05)
between the two groups are shown in Table 4. Physical
activity levels in the intervention group increased
(+14.78 METs x h/week), whereas the control group
did not change significantly.
Significant reductions in FBS (t ¼ 2:26; po0:05) and
HbA1c (t ¼ 2:44; po0:05) between the two groups are
shown in Table 3. In the intervention group FBS
decreased (17.18 mg/dl), whereas in the control group
it increased (+10.61 mg/dl). With regard to HbA1c, the
intervention group decreased (0.88%), whereas the
control group increased (+0.41%).
4. Discussion
This is the first controlled SMI based on the TTM
designed to promote the adoption and maintenance of
exercise behavior in SK. This study showed that the SMI
for type 2 diabetic Korean participants improved SOC
for exercise behavior and physical activity levels, and
also decreased FBS and HbA1c.
The findings of this study were consistent with those
reported in Western countries (Calfas et al., 1996, 1997;
King et al., 2000; Lewis and Lynch, 1993; Marcus et al.,
1997). In terms of SOC, our findings are similar
to the significant differences in SOC that were found
between a control group and those who received a
stage-based intervention in the primary care setting
(Calfas et al., 1996, 1997; Lewis and Lynch, 1993;
Marcus et al., 1996, 1997). A high percentage (77.4%)
of the intervention group in our study progressed
in their SOC from baseline, while Lewis and Lynch
(1993) reported that only 52% in their intervention
group progressed. When comparing SOC of the
present study with previous research, we also find that
higher shift in stage is comparable to a previous study
where 26% of a worksite health promotion project
sample progressed a stage, 15% regressed or relapsed
and 59% maintained (Calfas et al., 1997). It is
important to note that our study did find that staged
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Table 4
Group differences in movement through the SOC
SOC
Pre-contemplation stage
Baseline
Posttest
Contemplation stage
Baseline
Posttest
Preparation stage
Baseline
Posttest
Action stage
Baseline
Posttest
Maintenance stage
Baseline
Posttest
Intervention group (n ¼ 22)
Control group (n ¼ 23)
Mean
Number
Mean
Number
Z
p
1.00
3.00
SP:2
1.00
1.33
SP:1, SM:2
1.83
0.07
2.00
4.00
SP:4
2.00
2.25
SM: 3, SR:1
2.00
0.046
3.00
4.00
SP: 5
3.00
2.83
SM: 4, SR: 2
2.52
0.01
4.00
4.80
SP: 5
4.00
3.80
SM: 4, SR: 1
2.43
0.03
5.00
5.00
SM: 5, SR: 1
5.00
5.00
SM: 5
0.00
1.000
SOC denotes ‘‘stages of change’’, SP denotes ‘‘stage progressed’’, SM denotes ‘‘stage maintained’’, and SR denotes ‘‘stage regressed’’.
approaches also resulted in a shift in stage in a clinical
setting.
Significant changes in SOC resulted in concomitant
changes in physical activity levels. Both physical activity
levels and SOC also increased in our study. This finding
is similar to the results of other studies (Calfas et al.,
1996; King et al., 2000; Marcus and Simkin, 1993). This
finding also supports previous result that found significant increases in both SOC and physical activity
levels when physical activity was measured by walking
and accelerometer scores (Calfas et al., 1996). The
intervention group in our study increased physical
activity levels from 14.65 to 29.43 METs x h/week. This
finding in our study for all stages (PC to M) is higher
than in a previous study for only sedentary patients (PC
to P) with type 2 DM (Loreto et al., 2003). Loreto et al.
(2003) have reported that their diabetic intervention
group after having participated in a 2-year physician
based physical activity counseling program increased
physical activity levels from 0.8 to 27.1 METs x h/week.
Recently, American College of Sports Medicine
(ACSM) developed a new protocol to promote health
through an accessible exercise program that includes
populations with various chronic diseases (ACSM,
2000). For example, some studies report that even
moderate physical activity is also useful (Burns, 1996;
Houde and Melillo, 2000). Moderate physical activities
are the same as walking 3–4 miles/h, consuming about
3–6 METs. This intensity is the one with which most
people feel comfortable. Thirty minutes of continued
physical activity or the sum of at least 30 min of
intermittent exercise, 8–10 min per session, are considered moderate physical activities. Grounded in this
background, the present study was done for participants
in the early stages (PC to C) who had difficulty engaging
in exercise. The types of moderate physical activities in
our study were brisk walking, step climbing, taking a
walk, and household, leisure, and job activity. The initial
goal was set to at least 5 min of physical activity and
then gradually increased to reach 30 min.
Significant differences in FBS and HbA1c were shown
between the two groups in this study. These findings
were consistent with those reported in previous studies
among Korean diabetic participants (Hwang et al.,
2000, 2001; Jun, 1994; Kim, 1989; Lee, 1990; Na et al.,
1993). These findings are also similar to those of
Western countries. For example, Agurs et al. (1997)
reported that FBS and HbA1c decreased in type 2
diabetic participants after 12 weeks of aerobic exercise.
In a moderate circuit training exercise study (Honkola
et al., 1997) for type 2 diabetic participants, the
intervention group significantly decreased HbA1c, compared to the control group. With regard to the clinical
significance of our study, the observed outcome such as
the reduction of HbA1c to below 7% can prevent
diabetic complication. Similarly, data from the United
Kingdom prospective diabetes study demonstrated that
improving glycemic control by 0.9% reduced complications by 12% (i.e. diabetic retinopathy, nephropathy,
and peripheral neuropathy, etc.) (Natarajan et al., 2002).
Some limitations of this study deserve mention. First,
our sample was very small for conducting any meaningful analyses because individuals are categorized into
SOC. The average of effect size changes in our study was
calculated 0.92 (SD 0.40, range 0.61–1.49). However,
large numbers of samples are required because there are
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five categories in the TTM. Also, We had differences
in SD for age between the intervention and the
control groups in our study because of the lack of
random assignment. This convenience sampling procedures used to recruit participants increased the possibility of bias.
Nevertheless, the importance of the SMI to nursing
theory is the use of theoretical framework such as TTMderived constructs to apply the exercise behavior change
intervention. Most exercise interventions are designed
without theoretical framework or for individuals who
only do some exercise (P to A stages). When there is a
mismatch between participants’ stages of readiness for
change and the intervention strategy used, they are more
likely to drop out of the program (Marcus et al., 1992;
Marcus and Forsyth, 2003). Matching intervention
strategies to people’s stages of readiness for change,
such as the SMI, can improve not only the likelihood
that they will regularly attend a program but also
decreases the likelihood that they will stop participating
in the program.
Another potential importance of the SMI to nursing
practice is its usefulness for participants (PC to C)
who are likely to most need to change, yet few
opportunities for change are offered to them.
Many times these people are not motivated enough
to seek out opportunities on their own. However,
more than half the population is in early stages (PC
to C). For instance, we studied a sample of Korean
participants with type 2 diabetes (Kim, 2002a), and
classified 15% in pre-contemplation stage, 33%
in contemplation stage, 17% in preparation stage,
16% in action stage, and 19% in maintenance
stage. Health providers in nursing practice or medical
settings also need to be interested in helping people lead
more active lives and need to think about other types of
programs, such as the SMI, to offer participants who are
in early stages.
5. Conclusions
The findings of this study conclude that the SMI
may be useful by improving SOC for exercise
behavior and physical activity levels, and also by
decreasing FBS and HbA1c in participants with type 2
Diabetes. Future studies are suggested: (a) a study
including a larger sample size; (b) a study examining its
effectiveness in a variety of settings; (c) a study
investigating the methods of delivering intervention;
and (d) a comparative study examining the effectiveness
of these two types of exercise behavior: thirty minutes of
continued exercise behavior versus the sum of at least
30 min of intermittent exercise behavior, 8–10 min
per session.
Acknowledgements
The authors acknowledge with gratitude the editorial
suggestions of Dr. M. Storey and N. Abney, the most
competent assistance of Drs. J-.H. Kim, H-.C. Lee,
H-.C. Ooh, J-.Y. Kwan, D-.J. Kim, S-.W. Lee, M.D.s,
and the cooperation of participants and clinical staffs of
the Outpatient Diabetes Center, Yonsei Medical Center,
Seoul, South Korea.
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