Background: Among individuals with COPD, physical activity (PA) is critical for maintaining physical functioning. However, depression is a known barrier to PA. This study examined whether baseline depression symptoms moderated response to a pedometer-mediated, web-based PA intervention.
Methods: This secondary analysis included three cohorts of Veterans (N = 375) with COPD and measures of depression symptoms (Beck Depression Inventory-II [BDI-II]) and daily step counts at baseline (Time 1) and 3 months (Time 2). In two cohorts (Cohort 2 and 3), participants were randomly assigned to the same web-based, pedometer-mediated PA intervention (n=111) or usual care (UC; n=101). The intervention consisted of a pedometer plus a website that provided goal setting, feedback, motivational messages, educational content, and social support. Participants in Cohort 1 (n=163) participated in an observational study and were considered to be part of UC. Linear regression tested the moderating effect of depression symptoms on the association between group assignment and change in daily step count at Time 2 controlling for age, forced expiratory volume in first second percent predicted, body mass index, and season.
Results: The following predicted less change in daily step count at Time 2: greater baseline daily step count, participating in the summer or fall vs. the winter, and greater baseline depression symptoms. There was a significant interaction between baseline depression symptoms and randomization group predicting change in daily step count. We evaluated the difference in Time 2 daily step count between the intervention and UC groups when BDI-II score was at the mean ± 1 SD. When BDI-II scores were at the mean or 1 SD below, there was a significant association between the intervention group and Time 2 daily step count. When BDI-II scores were 1 SD above the mean, the association between the intervention group and Time 2 daily step count was no longer significant.
Conclusions: Future research should examine the mechanisms by which depression impacts response to PA promotion in COPD and tailor PA interventions to address low PA and significant depression symptoms.
Live Zoom Session – March 9th
Christine Perndorfer, MS, MA, Patricia Bamonti, PhD, Stephanie A. Robinson, PhD, Maria Mongiardo, MPH, Marilyn L. Moy, MD, MSc
Marilyn Moy, MD, MSc