Objective: To develop and test the intra-rater reliability of an interview-administered questionnaire that assesses lifetime patterns of total physical activity including occupational, household, and exercise/sports activities.
Methods: The questionnaire was developed and pretested using cognitive interviewing techniques on a sample of women with and without previous breast cancer diagnoses. A pilot study was conducted with 115 women who were interviewed twice, 6 to 8 wk apart by interviewers trained in cognitive interviewing methods. Respondents used recall calendars to record their education, occupations, life events, and physical activity patterns before the interviews. Interviewers helped respondents recall their lifetime exposures, including their occupational, household, and exercise/sports activities, using these calendars and memory-probing strategies. Activity levels were estimated as the average number of hours of activity per week over different time periods. Means and correlation coefficients were estimated and compared for the two time periods.
Results: The questionnaire was found to be highly reliable. The test-retest correlations for hours per week spent in total lifetime physical activity was 0.74, for lifetime occupational activity was 0.87, for household activity was 0.77, and for exercise/sports activities was 0.72.
Conclusions: This is the first questionnaire to measure lifetime physical activity by collecting data on each type of physical activity separately over lifetime and by measuring frequency, intensity, and duration of each activity. It is also the first physical activity questionnaire to be developed, refined, and administered using cognitive-based methods employed in survey research. Respondents were able to reliably recall their lifetime physical activity patterns. This instrument can be used for any disease outcome for which physical activity may be a risk factor.
Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, 1331-29 St. N.W. Calgary, Alberta, T2N 4N2 CANADA; and Faculty of Physical Education and Recreation, University of Alberta, Alberta, CANADA
Submitted for publication July 1996.
Accepted for publication July 1997.
This work was funded by a research grant from the Alberta Cancer Board's Research Initiative Program.
C. M. Friedenreich is supported by a National Health Research Scholar Award from the National Health Research and Development Program of Health Canada.
Address for correspondence: Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, 1331-29 St. N.W. Calgary, Alberta, T2N 4N2. E-mail: email@example.com.