Comparison of regression models for the analysis of fall risk factors in older veterans

To compare the performance of eight regression models for analyzing risk of falling, focusing on the effect of physical inactivity in older veterans.

This study uses data from a fall risk factor screening and modification trial in community-dwelling Canadian male veterans of World War II or the Korean War, with falls ascertained prospectively using calendars and physical activity (PA) measured at baseline with a single global question. The effect of PA on falling was assessed using eight different multivariable regression models, with three models treating falling as a non-recurrent event whereas the other five models regard falls as recurrent events.

Recurrent event models showed that male veterans who reported being less active than their peers were 1.42 (1.02-1.97) to 2.46 (1.18-5.14) times more likely to fall than those who reported being about as or more active than their peers (n = 270; mean age +/- SD = 81.1 +/- 4.0 years). None of the non-recurrent event models detected a statistically significant association between PA and falls.

Risk of falling may be better analyzed using regression models for recurrent events. These results have important implications for the collection and analysis of fall outcome data.