Physical Activity, Sedentary Behavior, And Social Cognitive Factors In Inactive, Breast And Endometrial Cancer Survivors Using Ecological Momentary Assessment

PURPOSE: To examine same-day relationships between social cognitive theory (SCT) factors and activity behaviors among insufficiently active breast and endometrial cancer survivors. METHODS: Survivors (N = 127, Mage = 56.3 ± 9.6 years, MBMI = 3.8 ± 7.9 kg/m2) wore an ActiGraph accelerometer to assess daily activity (SB, light intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA)) and completed ecological momentary assessment prompts in the morning within 2 hours of their usual wake time to assess current day’s SCT factors (exercise self-efficacy, function and psychological outcome expectations (OE) for exercise, exercise plans, and social support for exercise) for 7 consecutive days as part of baseline assessments for a physical activity intervention. Self-efficacy was on a 100-pt scale in increments of 10. All other SCT factors were on a 5-pt scale. Separate mixed-effects models assessed the between-person (BP) and within-person (WP) associations between each daily SCT factor and minutes of SB, LPA, and MVPA that same day, controlling for relevant covariates (age, BMI, cancer type, wear time). RESULTS: Survivors were highly sedentary (516 ± 96 minutes) and averaged 271 ± 90 minutes of LPA and 17 ± 10 minutes of MVPA per day. WP associations were significant for functional (β = -32 ± 14 minutes, p = 0.028) and psychological OE (β = -55 ± 22 minutes, p = 0.013) and SB such that when participants reported higher OE than their average on a given day, they spent less time sedentary that day. There were no significant WP associations for self-efficacy, or social support for any intensity. There was a significant BP association for social support (β = 5 ± 1 minutes, p = 0.004) on MVPA such that those with greater social support spent more time in MVPA. There were significant BP associations for self-efficacy (β = -1 ± 0.3 minutes, p = 0.02), functional OE (β = -27 ± 12 minutes, p = 0.02), and psychological OE (β = -23 ± 11 minutes, p = 0.04) on SB such that those with higher SCT ratings spent less time sedentary. CONCLUSIONS: Results indicate that daily SCT factors are important to consider when developing interventions to reduce SB for inactive breast and endometrial cancer survivors. Understanding daily fluctuations and SCT factors’ influence on subsequent days’ activity behaviors, is warranted in future research.