Comparing Estimates of Fall-related Mortality Incidence among Older Adults in the United States

Background: Falls are the leading cause of injury-related mortality among older adults in the United States, but incidence and risk factors for fall-related mortality remain poorly understood. This study compared fall-related mortality incidence rate estimates from a nationally-representative cohort to those from a national vital records database and identified correlates of fall-related mortality.

Methods: Cause-of-death data from the National Death Index (NDI; 1999-2011) were linked with eight waves from the Health and Retirement Study (HRS), a representative cohort of US older adults (N=20,639). Weighted fall-related mortality incidence rates were calculated and compared with estimates from the CDC vital records data. Fall-related deaths were identified using International Classification of Diseases (Version 10) codes. Person-time at risk was calculated from HRS study entry until death or censoring. Cox proportional hazards models were used to identify individual-level factors associated with fall-related deaths.

Results: The overall incidence rate of fall-related mortality was greater in HRS-NDI data (51.6 deaths per 100,000; 95% CI: 42.04, 63.37) compared to CDC data (42.00 deaths per 100,000; 95% CI: 41.80, 42.19). Estimated differences between the two data sources were greater for men and adults age 85 and older. Greater age, male gender, and self-reported fall history were identified as independent risk factors for fall-related mortality.

Conclusion: Incidence rates based on aggregate vital records may substantially underestimate the occurrence of and risk for fall-related mortality differentially in men, minorities, and relatively younger adults. Cohort-based estimates of individual fall-related mortality risk are important supplements to vital records estimates.