Background It is important to quantify the comparative importance of influencing factors of falls and fall-induced injuries among the elderly. This important research question, however, has not been examined through a rigorous design.

Objective To compare the relative importance of 11 common influencing factors of falls and fall-induced injuries that were documented in literature.

Methods Data were derived from five-round follow-ups (2, 3, 4, 5, 7 years) of the China Health and Retirement Longitudinal Study (CHARLS) between 2011 and 2018. Binary logistic regression and negative binomial regression were employed to test the significance of correlations between 11 factors and the occurrence of falls and fall-induced injuries in five-round follow-ups. Standardized regression coefficients were used to quantify the relative importance of 11 influencing factors.

Results This study included 9279, 6153, 4142, 4148, and 3583 elderly individuals in five-round follow-ups. The cumulative incidence rate of falls over 2, 3, 4, 5, and 7 years of follow-up was 19.4% (95% CI: 18.6–20.2%), 22.1% (95% CI: 21.0–23.1%), 31.9% (95% CI: 30.4–33.3%), 35.1% (95% CI: 33.6–36.5%), and 43.2% (95% CI: 41.6–44.8%), respectively. The corresponding cumulative incidence rate of fall-induced injuries at five follow-ups were 8.4% (95% CI: 7.8–8.9%), 9.4% (95% CI: 8.7–10.1%), 15.1% (95% CI: 14.0–16.2%), 16.2% (95% CI: 15.1–17.3%), and 22.0% (95% CI: 20.6–23.3%). Multivariate logistic regression and negative binomial regression analyses showed: (1) Of the 11 factors, only gender, history of falls, and the presence of depressive symptoms were identified as common risk factors of falls and fall-induced injuries among the elderly Chinese in five-round follow-ups (P<0.05); and (2) of the 11 factors, the history of falls and gender had the highest absolute values of standardized regression coefficients, respectively ranking the first and second places.

Conclusion Of the 11 influencing factors of falls and fall-induced injuries reported by previous literature, only gender, history of falls, and the presence of depressive symptoms were identified as common risk factors of falls and induced injuries among old Chinese in the five follow-up visits. Of the 11 influencing factors, history of falls and gender were two most important influencing factors of elderly falls and fall-induced injuries.