Beth A. Lewis

Psychosocial mediators of physical activity behavior among adults and children

BACKGROUND Researchers examining theory-based, physical activity (PA) interventions postulate that interventions are effective by changing theoretical constructs hypothesized to mediate the relationship between the intervention and PA behavior. Research indicates that PA interventions are effective for increasing PA behavior. However, whether effective interventions are due to predicted changes in theoretical constructs remains poorly understood. METHODS Studies that examined theoretical constructs (i.e., mediators) in PA interventions of adults or children, which used experimental designs and met other criteria for evaluating mediation, were collected via literature searches, personal searches of files, and personal communications. Only studies examining the direct effect of the intervention on the hypothesized mediator were considered relevant for this study. RESULTS Based on our criteria, the adult literature search yielded ten studies and the child literature search yielded two studies. The most common mediators examined included behavioral processes of change, cognitive processes of change, self-efficacy, decisional balance, social support, and enjoyment. Research indicates that behavioral processes are likely mediators. There was some support for the importance of self-efficacy as a mediator. CONCLUSIONS Few studies have used statistically recommended methods to examine mediators in PA intervention studies. Therefore, definitive conclusions about the importance of the mediators reviewed are not possible at this time. Additional PA mediator-intervention studies using recommended statistical methods are necessary to truly test if theory-based PA interventions are effective due to predicted changes in theoretical constructs.

Supervised Exercise Versus Primary Stenting for Claudication Resulting From Aortoiliac Peripheral Artery Disease Six-Month Outcomes From the Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) Study

Background— Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise (SE), or stent revascularization (ST). Methods and Results— We randomly assigned 111 patients with aortoiliac peripheral artery disease to receive 1 of 3 treatments: optimal medical care (OMC), OMC plus SE, or OMC plus ST. The primary end point was the change in peak walking time on a graded treadmill test at 6 months compared with baseline. Secondary end points included free-living step activity, quality of life with the Walking Impairment Questionnaire, Peripheral Artery Questionnaire, Medical Outcomes Study 12-Item Short Form, and cardiovascular risk factors. At the 6-month follow-up, change in peak walking time (the primary end point) was greatest for SE, intermediate for ST, and least with OMC (mean change versus baseline, 5.8±4.6, 3.7±4.9, and 1.2±2.6 minutes, respectively; P <0.001 for the comparison of SE versus OMC, P =0.02 for ST versus OMC, and P =0.04 for SE versus ST). Although disease-specific quality of life as assessed by the Walking Impairment Questionnaire and Peripheral Artery Questionnaire also improved with both SE and ST compared with OMC, for most scales, the extent of improvement was greater with ST than SE. Free-living step activity increased more with ST than with either SE or OMC alone (114±274 versus 73±139 versus −6±109 steps per hour), but these differences were not statistically significant. Conclusions— SE results in superior treadmill walking performance than ST, even for those with aortoiliac peripheral artery disease. The contrast between better walking performance for SE and better patient-reported quality of life for ST warrants further study. Clinical Trial Registration— URL: . Unique identifier: [NCT00132743][1]. # Clinical Perspective {#article-title-36} [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00132743&atom=%2Fcirculationaha%2F125%2F1%2F130.atomBackground Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise or stent revascularization.Background— Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise (SE), or stent revascularization (ST). Methods and Results— We randomly assigned 111 patients with aortoiliac peripheral artery disease to receive 1 of 3 treatments: optimal medical care (OMC), OMC plus SE, or OMC plus ST. The primary end point was the change in peak walking time on a graded treadmill test at 6 months compared with baseline. Secondary end points included free-living step activity, quality of life with the Walking Impairment Questionnaire, Peripheral Artery Questionnaire, Medical Outcomes Study 12-Item Short Form, and cardiovascular risk factors. At the 6-month follow-up, change in peak walking time (the primary end point) was greatest for SE, intermediate for ST, and least with OMC (mean change versus baseline, 5.8±4.6, 3.7±4.9, and 1.2±2.6 minutes, respectively; P<0.001 for the comparison of SE versus OMC, P=0.02 for ST versus OMC, and P=0.04 for SE versus ST). Although disease-specific quality of life as assessed by the Walking Impairment Questionnaire and Peripheral Artery Questionnaire also improved with both SE and ST compared with OMC, for most scales, the extent of improvement was greater with ST than SE. Free-living step activity increased more with ST than with either SE or OMC alone (114±274 versus 73±139 versus −6±109 steps per hour), but these differences were not statistically significant. Conclusions— SE results in superior treadmill walking performance than ST, even for those with aortoiliac peripheral artery disease. The contrast between better walking performance for SE and better patient-reported quality of life for ST warrants further study. Clinical Trial Registration— URL: http://clinicaltrials.gov/ct/show/NCT00132743?order=1. Unique identifier: NCT00132743.

The efficacy of moderate-intensity exercise as an aid for smoking cessation in women: a randomized controlled trial.

Evidence suggests that vigorous-intensity exercise interventions may be effective for smoking cessation among women; however, few studies have examined the efficacy of a moderate-intensity exercise program. The present study examined the efficacy of moderate-intensity exercise for smoking cessation among female smokers. Healthy, sedentary female smokers (N = 217) were randomly assigned to an 8-week cognitive-behavioral smoking cessation program plus moderate-intensity exercise (CBT+EX) or to the same cessation program plus equal contact (CBT). A subsample received nicotine replacement therapy. Results indicated that the CBT+EX and CBT groups were equally likely to attain smoking cessation at the end of treatment, as measured by cotinine-verified 7-day point-prevalence abstinence (20.2% for CBT+EX vs. 18.5% for CBT). The CBT+EX group was more likely to report smoking cessation, as measured by 7-day point prevalence at the 3-month follow-up (11.9% vs. 4.6%, p<.05), compared with the CBT group. No group differences were found at 12 months by either 7-day point prevalence (7.3% for CBT+EX vs. 8.3% for CBT) or continuous abstinence (0.9% for CBT+EX vs. 0.9% for CBT). Additionally, among participants in the CBT+EX group, those with higher adherence to the exercise prescription were significantly more likely to achieve smoking cessation at the end of treatment than were participants reporting lower adherence to exercise. Our findings indicate that the empirical support for moderate-intensity exercise as an adjunctive treatment to CBT for smoking cessation may be limited. Perhaps future studies could compare moderate- vs. vigorous-intensity physical activity to test their relative efficacy.

Mindfulness-Based Stress Reduction for Family Caregivers: A Randomized Controlled Trial

PURPOSE Caring for a family member with dementia is associated with chronic stress, which can have significant deleterious effects on caregivers. The purpose of the Balance Study was to compare a mindfulness-based stress reduction (MBSR) intervention to a community caregiver education and support (CCES) intervention for family caregivers of people with dementia. DESIGN AND METHODS We randomly assigned 78 family caregivers to an MBSR or a CCES intervention, matched for time and attention. Study participants attended 8 weekly intervention sessions and participated in home-based practice. Surveys were completed at baseline, postintervention, and at 6 months. Participants were 32- to 82-year-old predominately non-Hispanic White women caring for a parent with dementia. RESULTS MBSR was more effective at improving overall mental health, reducing stress, and decreasing depression than CCES. Both interventions improved caregiver mental health and were similarly effective at improving anxiety, social support, and burden. IMPLICATIONS MBSR could reduce stress and improve mental health in caregivers of family members with dementia residing in the community.

MEDIATORS OF PHYSICAL ACTIVITY BEHAVIOR CHANGE: A MULTIVARIATE APPROACH

OBJECTIVE Using a multivariate extension of the Baron and Kenny (1986) mediation framework, we examined the simultaneous effect of variables hypothesized to mediate the relationship between a motivationally tailored physical activity intervention, and 6-month physical activity behavior in 239 healthy, underactive adults (M age = 47.5; 82% women). DESIGN Participants were randomly assigned to (a) print-based feedback; (b) telephone-based feedback; or (c) contact control. MAIN OUTCOME MEASURES Psychosocial variables, including self-efficacy, decisional balance, and processes of change. RESULTS All mediation criteria were satisfied for both intervention arms. A moderate indirect effect of print (0.39, 95% CI = 0.21, 0.57) was found due to increases in behavioral processes (0.54, 95% CI = 0.29, 0.80) being attenuated by decreases due to cognitive processes (-0.17, 95%CI = 0.31,-.03). A moderate indirect effect was observed for telephone (0.47, 95% CI = 0.28, 0.66), with increases due to behavioral processes (0.61, 95% CI = 0.34, 0.87) attenuated by decreases due to cognitive processes (0.15, 95% CI = -0.27, -0.02); self-efficacy and decisional balance mediational paths did not attain statistical significance. CONCLUSIONS These findings highlight the importance of studies that deconstruct the theoretical components of interventions to determine which combination produces the greatest behavior changes at the lowest cost.

Supervised Exercise, Stent Revascularization, or Medical Therapy for Claudication Due to Aortoiliac Peripheral Artery Disease: The CLEVER Study

BACKGROUND Treatment for claudication that is due to aortoiliac peripheral artery disease (PAD) often relies on stent revascularization (ST). However, supervised exercise (SE) is known to provide comparable short-term (6-month) improvements in functional status and quality of life. Longer-term outcomes are not known. OBJECTIVES The goal of this study was to report the longer-term (18-month) efficacy of SE compared with ST and optimal medical care (OMC). METHODS Of 111 patients with aortoiliac PAD randomly assigned to receive OMC, OMC plus SE, or OMC plus ST, 79 completed the 18-month clinical and treadmill follow-up assessment. SE consisted of 6 months of SE and an additional year of telephone-based exercise counseling. Primary clinical outcomes included objective treadmill-based walking performance and subjective quality of life. RESULTS Peak walking time improved from baseline to 18 months for both SE (5.0 ± 5.4 min) and ST (3.2 ± 4.7 min) significantly more than for OMC (0.2 ± 2.1 min; p < 0.001 and p = 0.04, respectively). The difference between SE and ST was not significant (p = 0.16). Improvement in claudication onset time was greater for SE compared with OMC, but not for ST compared with OMC. Many disease-specific quality-of-life scales demonstrated durable improvements that were greater for ST compared with SE or OMC. CONCLUSIONS Both SE and ST had better 18-month outcomes than OMC. SE and ST provided comparable durable improvement in functional status and in quality of life up to 18 months. The durability of claudication exercise interventions merits its consideration as a primary PAD claudication treatment.

The Effect of Exercise During Pregnancy on Maternal Outcomes: Practical Implications for Practice

The American College of Obstetricians and Gynecologists recommends that women with low-risk pregnancies participate in moderate-intensity exercise during their pregnancy. Currently, only 15.1% of pregnant women exercise at the recommended levels, which is significantly lower than the general populations 45%. One potential reason is that exercise during pregnancy is perceived as risky. In this article, the authors provide a critical review of the literature examining the effect of exercise on preeclampsia, gestational diabetes, weight gain, labor and birth, and other issues associated with pregnancy. Overall, the evidence indicates that exercise during pregnancy is safe and perhaps even reduces the risk of preeclampsia and gestational diabetes. The evidence for weight gain and labor and birth (rates of cesarean sections, duration of labor) is mixed. Unfortunately, much of the research examining exercise during pregnancy is observational, and the few randomized controlled trials that do exist are small and inadequately powered. Taken together, given the potential benefits of exercise during pregnancy and the lack of evidence for harmful effects on the mother and newborn, practitioners should encourage their healthy pregnant patients to exercise. Practical guidelines for recommending exercise to pregnant women are presented.

Feasibility of an exercise counseling intervention for depressed women smokers.

INTRODUCTION Depressive symptoms negatively impact smoking abstinence. However, few interventions have been targeted to smokers with current depression. Exercise improves mood and may benefit depressed smokers. This pilot study investigated the feasibility of an exercise intervention for depressed female smokers (Center for Epidemiological Studies Depression Scale [CES-D] score > or =16). METHODS Participants (M = 41 years, 98% White) were randomized to 10 weeks of individually delivered exercise counseling (n = 30) or a health education contact control condition (n = 30). All participants received nicotine patch therapy and behavioral counseling for smoking cessation. RESULTS The intervention was feasible as indicated by ability to recruit participants, exercise counseling session attendance (M = 7.6 of 10 sessions attended), and significant increase in exercise frequency and stage of change from baseline to end of treatment (EOT) (Week 10). Participant attrition rate was 35% by Week 10 but did not differ significantly between groups. Smoking abstinence rates at Week 10, using intention-to-treat analysis, were 17% for exercise counseling participants and 23% for health education participants (p = .75). DISCUSSION An exercise counseling intervention was found to be feasible for depressed women smokers. More intensive intervention may be needed to increase smoking abstinence rates, and methods should be refined to reduce participant burden and attrition.

User attitudes towards physical activity websites in a randomized controlled trial

OBJECTIVE To better understand the mixed findings regarding the efficacy of Internet-based physical activity interventions, we examined the use and usefulness of particular website components that may lead to improvements in intervention efficacy. METHOD Participants were sedentary individuals from a 12-month randomized controlled physical activity trial conducted in Providence, Rhode Island and Pittsburgh, Pennsylvania from 2003-2006. The present study included participants from the Tailored Internet arm (n=81; instantaneous web-based tailored feedback to participants) or the Standard Internet arm (n=82; websites currently available to the public). We obtained objective data via the intervention websites and subjective usefulness data via questionnaires. RESULTS The Tailored Internet arm logged onto their website significantly more times than the Standard Internet arm (median 50 vs. 38; p<.05). Among participants in the Tailored Internet arm, the self-monitoring feature (i.e., logging) followed by goal setting were rated as the most useful website components. CONCLUSION Logins in the current study were substantially higher compared to previous studies. Participants endorsed goal setting and self-monitoring as being most useful, which are critical components for health behavior change. Future studies should continue to examine these features and improve the perceived usefulness of other theory-based strategies.

Older Adults’ Experiences Using a Commercially Available Monitor to Self-Track Their Physical Activity

Background Physical activity contributes to older adults’ autonomy, mobility, and quality of life as they age, yet fewer than 1 in 5 engage in activities as recommended. Many older adults track their exercise using pencil and paper, or their memory. Commercially available physical activity monitors (PAM) have the potential to facilitate these tracking practices and, in turn, physical activity. An assessment of older adults’ long-term experiences with PAM is needed to understand this potential. Objective To assess short and long-term experiences of adults >70 years old using a PAM (Fitbit One) in terms of acceptance, ease-of-use, and usefulness: domains in the technology acceptance model. Methods This prospective study included 95 community-dwelling older adults, all of whom received a PAM as part of randomized controlled trial piloting a fall-reducing physical activity promotion intervention. Ten-item surveys were administered 10 weeks and 8 months after the study started. Survey ratings are described and analyzed over time, and compared by sex, education, and age. Results Participants were mostly women (71/95, 75%), 70 to 96 years old, and had some college education (68/95, 72%). Most participants (86/95, 91%) agreed or strongly agreed that the PAM was easy to use, useful, and acceptable both 10 weeks and 8 months after enrolling in the study. Ratings dropped between these time points in all survey domains: ease-of-use (median difference 0.66 points, P=.001); usefulness (median difference 0.16 points, P=.193); and acceptance (median difference 0.17 points, P=.032). Differences in ratings by sex or educational attainment were not statistically significant at either time point. Most participants 80+ years of age (28/37, 76%) agreed or strongly agreed with survey items at long-term follow-up, however their ratings were significantly lower than participants in younger age groups at both time points. Conclusions Study results indicate it is feasible for older adults (70-90+ years of age) to use PAMs when self-tracking their physical activity, and provide a basis for developing recommendations to integrate PAMs into promotional efforts. Trial Registration Clinicaltrials.gov NCT02433249; https://clinicaltrials.gov/ct2/show/NCT02433249 (Archived by WebCite at http://www.webcitation.org/6gED6eh0I)