Objectives: To compare persons with and without hip fracture for subsequent mortality and change in disability and nursing home (NH) use.
Design: Population-based historical cohort study.
Setting: Olmsted County, Minnesota.
Participants: All residents who experienced a first hip fracture between January 1, 1989, and December 31, 1993, and, for each case, a resident of the same sex and similar age who had not experienced a hip fracture and was seen by a local care provider.
Measurements: Data on disability (Rankin score), comorbidity (Charlson Index), and NH residency before baseline (fracture date for cases and registration date for controls) were obtained by review of complete community-based medical records. The records were then reviewed from baseline through December 31, 1994, for Rankin disability at 1 month and 1 year, all NH admissions and discharges, and date of death for those who died.
Results: There were 312 cases and 312 controls (81% female, mean age +/- standard deviation = 81 +/- 12 years). Before baseline, cases had higher comorbidity (45% vs 30% had Charlson Index >/= 1, P <.001) and disability (mean Rankin score = 2.5 +/- 1.1 vs 2.2 +/- 1.1, P <.001) and were more likely to be in a NH (28% vs 18%, P <.001) than controls. One year after baseline, estimated mortality was 20% (95% confidence interval (CI) = 16-24) for cases vs 11% (95% CI = 8-15) for controls, 51% of cases versus 16% of controls had a level of disability one or more units worse than before baseline (P <.001), and the cumulative incidence of first NH admission was 64% (95% CI = 58-71) for cases versus 7% (95% CI = 4-11) for controls. The risk of NH admission for cases relative to controls diminished over time, but remained elevated 5 years after the event (risk ratio = 20.0 at 3 months and 2.1 at 5 years), but, in persons admitted to a nursing home, cases were two times more likely than controls to be discharged alive within a year (P <.001).
Conclusions: Hip fracture is an important contributor to disability and NH use, but the potential savings from hip fracture prophylaxis may be overestimated by studies that fail to consider differential risk, mortality, and long-term follow-up.