Sedentary behavior among breast cancer survivors: a longitudinal study using ecological momentary assessments

Purpose: Sedentary behavior (SB) or any waking behavior ≤ 1.5 METs is associated with an increase in body weight and fatigue and poor quality of life among cancer survivors. The purpose of this study was to explore longitudinal trends in SB using accelerometers and associated variables via ecological momentary assessments (EMA) among breast cancer survivors. Methods: Breast cancer survivors (within 5 years post-diagnosis) were recruited for a 12-month observational study. Participants were asked to download an EMA application to their smartphones to receive prompts for 7 days and to concurrently wear an Actigraph accelerometer. Participants responded to 35 prompts during each 7-day assessment period at baseline, and at 3, 6, 9, and 12 months. Within each prompt, participants were asked questions about their current level of affect, sadness, anxiety, stress, worry and fatigue, and cancer-related symptoms (e.g., neuropathy). Results: Twenty-two survivors (mean age = 51.5 years) were recruited and 20 participants completed the study. Mean baseline SB averaged 76.7 h/week. Univariate longitudinal models suggested higher levels of sadness, anxiety, stress, worry, and fatigue were associated with more SB while more positive affect was associated with less SB. Additionally, non-leisure context (work) was associated with more SB. Autoregressive models indicated cross-lagged effects of affective valence, fatigue, and SB. Conclusions: More negative affective valence and higher fatigue were associated with more SB. Reducing negative affect valence and offering non-sedentary approaches to manage fatigue may help reduce SB. Implications for Cancer Survivors: Specific interventions are needed to reduce SB among cancer survivors-particularly those that target negative affect valence and fatigue.