Predictors of long term mortality in older people with hip fracture

OBJECTIVE: To determine one year mortality and predisposing factors in older people who had surgery after a hip fracture.

DESIGN: Prospective cohort study.

SETTING: Public acute hospital, trauma service.

PARTICIPANTS: A total of 281 patients, 65 years or older, admitted with a hip fracture within one year from January 2009, and followed for one year thereafter.

INTERVENTIONS.: Not applicable MAIN OUTCOME MEASURE: Cumulative survival probability up to one year from surgery was calculated by means of Kaplan-Meier charts, and Cox regression models were performed to analyse the factors associated with mortality. Data were collected from medical charts and by interviews. Health status was evaluated using the American Society of Anaesthesiologists rating, prefracture functional level with the Functional Independence Measure, and cognitive status with the Pfeiffer score.

RESULTS: The one year mortality for the 281 patients followed was 21% (95% confidence interval [CI]=16.1-25.9%). A non-weight-bearing status was associated with increased mortality in unadjusted analyses (hazard ratio [HR]=1.99, 95%CI=1.16-3.43), but five other factors were identified when entered into the multiple Cox regression model; age (HR1.05, 95%CI= 1-1.09), men sex (HR=2.92, 95%CI=1.58-5.39), low health status (HR=2.8, 95%CI=1.29-6.09), low prefracture function (HR=0.98, 95%CI=0.97-0.99), and change of residence (HR=3.21, 95%CI=1.43-7.17).

CONCLUSION: The overall one-year mortality rate was 21%. Change of residence is the only potentially modifiable risk factor, independent of other traditional risk factors found, being; age, sex, health status and prefracture functional level. Still, 2-4 weeks of non weight-bearing status, which is considered modifiable, is also associated with increased mortality rates in unadjusted analyses.