Tricia Tang

South Asian immigrants are at high risk of chronic disease partly due to low levels of physical activity (PA). Accurate assessment of PA and sedentary time is imperative for monitoring PA trends and designing interventions. Few studies have used device-worn measures to assess PA and sedentary time in South Asians or investigated the potential association of socio-demographic factors. Objectives of this dissertation are to: 1) synthesize data on accelerometer-based studies in South Asians, 2) assess PA and sedentary time in a sample of South Asian adults using accelerometers, 3) examine potential socio-demographic correlates of PA and sedentary time, 4) and explore socio-cultural factors that influence PA.Methods: For objective 1, I systematically searched major databases for studies assessing device-worn measures of PA and sedentary time in South Asians. For objective 2 and 3, a subset of 100 South Asian participants self-reported socio-demographic information and wore Actical accelerometer for 7 days. For objective 4, I conducted four Focus Group Discussions (FGDs) with a sub-sample of 22 participants to understand socio-cultural influences of PA. Results: Only 14 studies used an accelerometer to measure PA and sedentary time with considerable variability in reported outcomes. In the accelerometer trial, participants accumulated 673.5 (95% CI: 656.6, 691.0) mean min/day of sedentary time, 130.5 (95% CI: 117.3, 145.3) min/day of light PA (LPA) and 6.8 (95% CI: 4.7, 10.1) min/day of moderate-to-vigorous PA (MVPA). Sex and Body Mass Index explained 51% of the variability in sedentary time and LPA. Sex and an interaction between education and presence of children under 12 explained 23% of the variability in MVPA. FGDs revealed participants’ understanding of PA was culturally embedded thus highlighting the need to understand influence of socio-cultural factors including immigration status on PA behavior.Conclusion: High sedentary time and low MVPA indicates a need to focus health promotion efforts on shifting sedentary time into LPA. FGDs reveal inadequate understanding of PA guidelines among women and difficulties in assessing intensity of activities. Self-report alone may not be an ideal method of PA assessment in South Asians. Future studies need to be based on representative samples of South Asians.

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BACKGROUND: The effects of peer support (PS) on clinical and psychosocial outcomes has been extensively studied in patients with type 2 diabetes, but only minimally examined in the peer leaders (PLs) who deliver support. This thesis’s objectives are to: examine PLs’ sociodemographic and personality characteristics, assess the clinical and psychological benefits of providing support; and identify strategies to improve PS interventions. METHODS: A sequential explanatory mixed-methods research design approach was utilized. The studies conducted for this thesis were extensions of a larger randomized controlled trial assessing the impact of PS on diabetes-related health outcomes. Fifty-two recruits completed PL training and were matched with participants on schedule availability, gender preference, and geographic proximity. PLs and participants had an initial face-to-face meeting, then weekly phone contacts in the first 3 months and bi-weekly phone contacts in the last 9 months. PLs underwent health-related assessments at baseline, 3, and 12 months. The primary outcomes were A1C and diabetes distress (DD). At study completion, PLs were deemed effective if their participants sustained and/or improved A1C and DD from baseline. The PLs’ sociodemographic and personality characteristics were also measured. To explore PLs’ perspectives, 17 PLs were subsequently invited for semi-structured interviews. RESULTS: PLs’ A1C and DD remained stable over the course of the intervention. Effective PLs had significantly lower baseline DD and significantly higher extraversion than ineffective PLs. During the interviews, PLs characterized their experiences with participants as positive, mutually beneficial, and helpful with diabetes management. Suggestions were that PLs be vigorously screened and that the PL-participant matching process take shared characteristics (e.g., demographic characteristics, diabetes-related commonalities, and life experiences) into account. Traits of successful PLs were also identified.CONCLUSION: Delivering PS interventions may offer clinical and psychosocial benefits to the providers themselves. Further research is warranted with regard to the PL recruitment and matching process to maximize benefits for PLs and participants.

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