Risk factors for hip fracture sites and mortality in older adults.

Background: Our study was designed to (1) investigate the risk factors associated with cervical or trochanteric hip fractures; and (2) identify the risk factors for increased mortality in the elderly population sustaining hip fractures, after adjusting the miscellaneous baseline prefracture conditions.

Methods: Two hundred seventeen elder patients with first-time, low-trauma hip fractures were enrolled. The follow-up time ranged from 35 months to 56 months. Potential risk factors for hip fracture types included (1) the 77 items on the self-reported questionnaire; (2) the body height, weight, and body mass index; (3) tests of coordination, handgrip strength, and peak expiratory flow rate; and (4) the bone mineral density variables. GTFN ratio was defined as the bone mineral density ratio between the greater trochanter and the femoral neck. Multivariate logistic regression and Cox regression models were used for analysis. The population attributable risk proportion of death to each significant factor was estimated.

Results: Risk factors for trochanteric fractures include a GTFN ratio ≤0.81, being male, and an age >80 years. Risk factors for higher mortality after hip fracture included trochanteric fracture, body mass index ≤20 (kg/m), poor self-assessed health status, peak expiratory flow rate ≤215 (L/min), being male, illiteracy, and coordination abnormality, in the declining order of population attributable risk proportion. Trochanteric fractures had a significantly higher cumulative mortality at 36 months, 48 months, and 60 months than cervical fractures.

Conclusions: The novel GTFN ratio was associated with hip fracture sites. Clinically, cervical and trochanteric fractures represent different disease entities because of the difference in their mortality rates.