Depression Symptoms and Physical Activity in Veterans With COPD: Insights From a Web-Based, Pedometer-Mediated Physical Activity Intervention

Abstract

Background Depression is known to limit physical activity (PA) among individuals with chronic obstructive pulmonary disease (COPD). However, whether and how depression influences the effectiveness of PA interventions is unknown. Purpose The study examined the association between baseline depression symptoms and change in daily step count and whether group assignment to a web-based, pedometer-mediated PA intervention moderated the association between baseline depression symptoms and change in daily step count. Methods Secondary analysis included two cohorts of U.S. Veterans with COPD (n = 212; 97% male; mean age 69 ± 8 years) assessed at baseline and 3 months. Cohorts 1 and 2 were randomly assigned to the same PA intervention (n = 111) or a control group (n = 101). Multivariate regressions tested the main effects of baseline depression symptoms (BDI-II total and cognitive-affective and somatic subscales) on change in daily steps, as well as the interaction between baseline BDI-II and subscales and group assignment on change in daily steps. Results Greater BDI-II total score (B = −31.8, SE = 14.48, p = .030) and somatic subscale scores (B = −99.82, SE = 35.76, p = .006) were associated with less improvement in daily step count. There was a significant interaction between baseline cognitive-affective subscale and the intervention predicting change in daily step count (B = −88.56, SE = 42.31, p = .038). When cognitive-affective subscale scores were ≥1 SD above the mean, the intervention was no longer associated with an increase in daily step count (p = .585). Conclusions Depression should be routinely assessed and targeted as part of PA promotion efforts.