A, Numbers below x-axis indicate participants who provided fall data. Overall, 10.5% of fall calendars (471/4472) were not returned. A total of 11 participants (3% of total randomized sample; 7 randomized to exercise and 4 randomized to usual care) did not provide any data related to falls after randomization. These participants dropped out within the first 2 months of the study. The estimated incidence rate of falls per person-year was 1.4 (95% CI, 0.1-2.0) in the exercise group and 2.1 (95% CI, 0.1-3.2) in the usual care group. The median total exposure was 365 (interquartile range [IQR], 365-365) days for both exercise and usual care. B, The median observation period from baseline to first fall was 173.5 (IQR, 58-365) days for the exercise group and 180.5 (IQR, 47.75-365) days for the usual care group. C, The median observation period after the first fall was 188 (IQR, 67-365) days for the exercise group and 161.5 (IQR, 52.5-365) days for the usual care group. In panels B and C, vertical lines on the curves indicate censored events.