Incidence of Lower-Extremity Fractures in US Nursing Homes

BACKGROUND/OBJECTIVES Limited studies suggest lower-extremity (LE) fractures are morbid events for nursing home (NH) residents. Our objective was to conduct a nationwide study comparing the incidence and resident characteristics associated with hip (proximal femur) vs nonhip LE (femoral shaft and tibia-fibula) fractures in the NH. DESIGN Retrospective cohort study. SETTING US NHs. PARTICIPANTS We included all long-stay residents, aged 65 years or older, enrolled in Medicare from January 1, 2008, to December 31, 2009 (N = 1 257 279). Residents were followed from long-stay qualification until the first event of LE fracture, death, or end of follow-up (2 years). MEASUREMENTS Fractures were classified using Medicare diagnostic and procedural codes. Function, cognition, and medical status were obtained from the Minimum Data Set prior to long-stay qualification. Incidence rates (IRs) were calculated as the total number of fractures divided by person-years. RESULTS During 42 800 person-years of follow-up, 52 177 residents had an LE fracture (43 695 hip, 6001 femoral shaft, 2481 tibia-fibula). The unadjusted IRs of LE fractures were 1.32/1000 person-years (95% confidence interval [CI] = 1.27-1.38) for tibia-fibula, 3.20/1000 person-years (95% CI = 3.12-3.29) for femoral shaft, and 23.32/1000 person-years (95% CI = 23.11-23.54) for hip. As compared with hip fracture residents, non-hip LE fracture residents were more likely to be immobile (58.1% vs 18.4%), to be dependent in all activities of daily living (31.6% vs 10.8%), to be transferred mechanically (20.5% vs 4.4%), to be overweight (mean body mass index = 26.6 vs 24.0 kg/m(2)), and to have diabetes (34.8% vs 25.7%). CONCLUSIONS Our findings that non-hip LE fractures often occur in severely functionally impaired residents suggest these fractures may have a different mechanism of injury than hip fractures. The resident differences in our study highlight the need for distinct prevention strategies for hip and non-hip LE fractures.