Does early functional outcome predict 1-year mortality in elderly patients with hip fracture?

Background: Hip fractures in the elderly are followed by considerable risk of functional decline and mortality.

Questions/purposes: The purposes of this study were to (1) explore predictive factors of functional level at discharge, (2) evaluate 1-year mortality after hip fracture compared with that of the general population, and (3) evaluate the affect of early functional outcome on 1-year mortality in patients operated on for hip fractures.

Methods: A total of 228 consecutive patients (average age, 77.6 ± 7.4 years) with hip fractures who met the inclusion criteria were enrolled in an open, prospective, observational cohort study. Functional level at discharge was measured with the motor Functional Independence Measure (FIM) score, which is the most widely accepted functional assessment measure in use in the rehabilitation community. Mortality rates in the study population were calculated in absolute numbers and as the standardized mortality ratio. Multivariate regression analysis was used to explore predictive factors for motor FIM score at discharge and for 1-year mortality adjusted for important baseline variables.

Results: Age, health status, cognitive level, preinjury functional level, and pressure sores after hip fracture surgery were independently related to lower discharge motor FIM scores. At 1-year followup, 57 patients (25%; 43 women and 14 men) had died. The 1-year hip fracture mortality rate compared with that of the general population was 31% in our population versus 7% for men and 23% in our population versus 5% for women 65 years or older. The 1-year standardized mortality rate was 341.3 (95% CI, 162.5-520.1) for men and 301.6 (95% CI, 212.4-391.8) for women, respectively. The all-cause mortality rate observed in this group was higher in all age groups and in both sexes when compared with the all-cause age-adjusted mortality of the general population. Motor FIM score at discharge was the only independent predictor of 1-year mortality after hip fracture.

Conclusions: Functional level at discharge is the main determinant of long-term mortality in patients with hip fracture. Motor FIM score at discharge is a reliable predictor of mortality and can be recommended for clinical use.