Risk Factors for Injurious Falls in Older Adults: The Role of Sex and Length of Follow-Up

OBJECTIVES: To identify sex-specific associations between risk factors and injurious falls over the short (<4 years) and long (4-10 years) term. DESIGN: Longitudinal cohort study between 2001 and 2011. SETTING: Swedish National Study on Aging and Care, Kungsholmen, Sweden. PARTICIPANTS: Community-dwelling adults aged 60 and older (N = 3,112). MEASUREMENTS: An injurious fall was defined as a fall that required inpatient or outpatient care. Information was collected on participant and exposure characteristics using structured interviews, clinical examinations, and physical function tests at baseline. RESULTS: The multivariate model showed that, in the short term, living alone (hazard ratio (HR)=1.83, 95% confidence interval (CI)=1.13-2.96), dependency in instrumental activities of daily living (IADLs) (HR=2.59, 95% CI=1.73-3.87), and previous falls (HR=1.71, 95% CI=1.08-2.72) were independently associated with injurious falls in women. Low systolic blood pressure (HR=1.96, 95% CI=1.04-3.71), impaired chair stands (HR=3.00, 95% CI=1.52-5.93), and previous falls (HR=2.81, 95% CI=1.32-5.97) were associated with injurious falls in men. Long-term risk factors were underweight (HR=2.03, 95% CI=1.40-2.95), cognitive impairment (HR=1.49, 95% CI=1.08-2.06), fall-risk increasing drugs (HR=1.67, 95% CI=1.27-2.20 for >= 2 drugs), and IADL dependency (HR=1.58, 95% CI=1.32-5.97) for women and smoking (HR=1.71, 95% CI=1.03-2.84), heart disease (HR=2.20, 95% CI=1.5-3.24), impaired balance (HR=1.68, 95% CI=1.08-2.62), and a previous fall (HR=3.61, 95% CI=1.98-6.61) for men. CONCLUSION: Men and women have different fall risk profiles, and these differences should be considered when developing preventive strategies. Some risk factors were more strongly predictive of injurious falls over shorter than longer periods and vice versa, suggesting that it may be possible to identify older men and women at short-and long-term risk of injurious falls.