Table 1.

Physical activity and falls collected in the Australian Longitudinal Study on Women’s Health (ALSWH)

Variable	Exposure and outcome collected in the ALSWH and how they were used in this study
Physical activity* (exposure)	Questions asked in the ALSWH (surveys 2–8) How many times did you do each type of activity last week? (only counted the number of times when the activity lasted for 10 min or more). Walking briskly (for recreation or exercise or to get from place to place). Moderate leisure activity (social tennis, moderate exercise classes, recreational swimming, dancing). Vigorous leisure activity (that makes one breath harder or puff and pant like aerobics, vigorous cycling, running, swimming). If you add up all the times you spent in each activity last week, how much time did you spend altogether doing each type of activity? Methods of categorising physical activity participation in this study The total amount of weekly physical activity participation was the sum of the above-mentioned three types of activities and was categorised into: 0, 1 to <150, 150 to <300 and ≥300 min
Falls (outcome)	Questions asked in the ALSWH†: In the last twelve months, have you Had a fall to the ground? Been injured as a result of a fall? Needed to seek medical attention for an injury from a fall? Methods of categorising falls in this study Participants were coded as having non-injurious falls if they reported a fall to the ground without a positive response to the second or third question about injury because of a fall and had injurious falls if they gave a positive response to the first and the second and/or third questions. The outcome was divided into three levels: no falls (reference group), non-injurious falls and injurious falls.

*To ensure the consistency of the questions asked about PA across all surveys, PA collected in survey 1 was not used as participants were asked to report the activity lasted for 20 min or more.

†Falls questions were included from survey 4 (2004).

PA, physical activity.