Abstract The impact of interventions to increase physical activity (PA) may vary as a function of participants' barriers to PA. The aim of this paper is to determine whether individual barriers ...(demographic, physical health, psychological health, neighborhood factors, perceived barriers to PA, social support for PA) moderate treatment effects on increases in PA. Three treatment conditions tested the relative efficacy of a group-based PA intervention alone or supplemented by either personal or automated phone calls made between group meetings. From 2010 to 2012, 284 African American women (ages 40–65) living in the Chicago, IL, area were randomized to one of the three treatment conditions. Data collection occurred at baseline as well as 24 and 48 weeks after baseline. Moderation of intervention effects by barriers to PA were tested across four outcome measures (self-reported moderate-vigorous PA, self-reported walking, accelerometer steps, and aerobic fitness) using multilevel mixed-effects analyses. Significant condition by barrier interaction effects for the accelerometer steps outcome were found for material hardships, general health, depressive symptoms, neighborhood crime rate, and perceived barriers to PA. For aerobic fitness, intervention effects were moderated by material hardships and perceived pain. Increases in the outcome variables were greater for the conditions in which group sessions were supplemented with personal and/or automated calls. Among participants with greater barriers to PA, supplementing the intervention group meetings with between-session personal and/or automated phone calls may be an effective way to strengthen intervention effects. These results may inform the use of treatment supplements in the context of adaptive interventions.
Abstract Although aggressive medical treatment protocols have led to 80% five-year survival rates for most childhood cancer patients, many long-term survivors experience multiple troubling symptoms. ...Using data from 100 adult survivors of childhood cancers (ACC-survivors), we used latent variable mixture modeling to generate unique subgroups of survivors based on their experiences with a cluster of eight symptoms: lack of energy, worry, pain, difficulty sleeping, feeling irritable, feeling nervous, difficulty concentrating, and feeling sad (as measured by the Memorial Symptom Assessment Scale). We also examined factors that were likely to predict subgroup membership (chronic health conditions CHCs, health-promoting lifestyle, and demographic variables) and determined the extent to which satisfaction with quality of life (QoL) varied across the subgroups. The final mixture model included three subgroups of ACC-survivors: high symptoms (HS; n = 21), moderate symptoms (MS; n = 45), and low symptoms (LS; n = 34). ACC-survivors who reported at least one CHC were six times as likely to be classified in the HS subgroup as compared with the LS subgroup. Mean health-promoting lifestyle scores were lowest in the HS subgroup and highest in the LS subgroup. Differences in QoL among the subgroups were statistically significant, thus validating that the subgroups were characterized uniquely for identifying those symptoms with highest life impact. To our knowledge, we are the first to identify distinct subgroups of ACC-survivors differentiated by symptom cluster experience profiles. The findings warrant additional research to confirm the subgroup-specific symptom cluster experience profiles in larger studies of ACC-survivors.
Abstract Objective To evaluate the marginal costs of increasing physical activity and maintaining weight for a lifestyle physical activity program targeting sedentary African American women. Methods ...Outcomes included change in minutes of total moderate to vigorous physical activity, leisure-time moderate to vigorous physical activity and walking per week, and weight stability between baseline and maintenance at 48 weeks. Marginal cost-effectiveness ratios (MCERs) were calculated for each outcome, and 95% confidence intervals (CIs) were computed using a bootstrap method. The analysis was carried out from the societal perspective and calculated in 2013 US dollars. Results For the 260 participants in the analysis, program costs were $165 ± $19, and participant costs were $164 ± $35, for a total cost of $329 ± $49. The MCER for change in walking was $1.50/min/wk (95% CI 1.28–1.87), for change in moderate to vigorous physical activity was $1.73/min/wk (95% CI 1.41–2.18), and for leisure-time moderate to vigorous physical activity was $1.94/min/wk (95% CI 1.58–2.40). The MCER for steps based on the accelerometer was $0.46 per step (95% CI 0.30-0.85) and weight stability was $412 (95% CI 399–456). Conclusions The Women’s Lifestyle Physical Activity Program is a relatively low-cost strategy for increasing physical activity. The marginal cost of increasing physical activity is lower than for weight stability. The participant costs related to time in the program were nearly half the total costs, suggesting that practitioners and policymakers should consider the participant cost when disseminating a lifestyle physical activity program into practice.