Grant: CIHR Fellowship

Introduction: Evidence is accumulating for the importance of 24-hour movement behaviours-physical activity, sedentary behaviours, and sleep-on a breadth of health outcomes at all ages. Statistics Canada's Canadian Health Measures Survey (CHMS) is the main surveillance tool for examining movement behaviours at a population level in Canada, and the CHMS is going from measuring isolated movement behaviours to measuring 24-hour movement behaviours. Changes will improve our understanding of movement behaviours in the Canadian population, but challenges in comparing past and future cycles will arise since the CHMS is switching: 1) movement behaviour measurement devices from Actical to ActiGraph accelerometers; 2) wear time protocols from awake wear time to 24-hour wear time protocols; 3) sleep measurement techniques from questionnaire to ActiGraph. Consequently, data discrepancies will occur because of different: device-specific outputs, patterns of missing data when comparing awake to 24-hour wear time protocols, and durations of sleep when comparing questionnaire and accelerometer estimates. The proposed research aims to develop techniques capable of valid and reliable comparisons across movement behaviour measurement cycles. Objective: Develop techniques to translate accelerometer outputs and compare trends in the movement behaviours of Canadians. Methods: Participants will simultaneously wear an Actical and ActiGraph accelerometer 24 hours/day for 7 days. Techniques will be created to: 1) translate Actical to ActiGraph outputs, 2) correct any missing data arising from awake wear time protocols, and 3) translate questionnaire and Actigraph sleep estimates. Significance: This research will allow Canada's evolving movement behaviour surveillance system to determine time trends in movement behaviours, and relationships with a variety of health outcomes, which are crucial for understanding the effectiveness of public health initiatives and steering public health policy.