Development and validation of a questionnaire for the assessment of physical activity in epidemiological studies in Sub-Saharan Africa

Objective To develop and validate a questionnaire for measuring physical activity within Sub-Saharan Africa. Methods We designed the Sub-Saharan Africa Activity Questionnaire (SSAAQ), based upon existing questionnaires and an activity survey carried out in Cameroon. The questionnaire targeted past-year occupation, walking/cycling and leisure-time activities, and was administered by trained interviewers on two occasions, 10-15 days apart to 89 urban and rural consenting Cameroonians aged 19-68 years. Reliability was assessed by inter-interview comparison and repeatability coefficients (standard deviation of the test-retest difference). Validation was performed against a 24-hour heart rate monitoring and accelerometer recording. Results The questionnaire was highly reproducible (rho = 0.95; P < 0.001). The interinterview difference did not differ significantly from 0, with a repeatability coefficient of 0.46-1.46 hours. Total energy expenditure from the questionnaire was significantly Correlated to heart rate monitoring (rho = 0.41-0.63; P < 0.05) and accelerometer measures (rho = 0.60-0.74; P < 0.01). Subject's self ranking of their activity did not match the questionnaire's quartiles of activity. Conclusions The present study presents the design and confirms the reliability and validity of SSAAQ in a rural and urban population of Cameroon and shows that subject's self ranking of activity might not accurately serve epidemiological purpose.