Development and validation of a clinical prediction rule for prolonged nursing home residence after hip fracture

OBJECTIVES: To develop and validate a clinical prediction rule for nursing home residence 6 months after a hip fracture. DESIGN: Two prospective cohort studies, a development study (DS) and a validation study (VS). SETTING: The DS included hip fracture patients admitted to 92 rehabilitation units or skilled nursing facilities; the VS included hip fracture patients from 11 integrated healthcare systems. PARTICIPANTS: A total of 344 community-dwelling hip fracture patients aged 65 and older participated in the DS; 239 similar patients were enrolled in the VS. INTERVENTION: None, MEASUREMENTS: The acute hospital record, nursing evaluations, and patient questionnaires provided information about demographics, physical and neuropsychological function, and comorbidity. Residence 6 months after fracture was determined by phone interview. Multivariate analysis identified predictors for a risk score to assess the likelihood of nursing home residence. RESULTS: 18.7% of patients in the DS resided in nursing homes 6 months after hip fracture. The four independent risk factors for institutionalization were (1) being unmarried (OR = 6.7 [95% CI 2.4 to 19]), (2) incontinence (OR = 2.3 [CI 1.2 to 4.7]), (3) dependence in ambulation (OR = 5.0 [CI 2.1 to 12.3]), and (4) cognitive impairment (OR = 6.6 [CI 3.3 to 13.2]). Of patients with all four risk factors, 73.2% were institutionalized at 6 months, compared with 0% of patients with no risk factors. In the VS, 6.1% of patients resided in nursing homes after 6 months, with a range from 50.0% of patients with four risk factors to 0% of those with no risk factors. Areas under receiver-operating characteristic curves for the prediction rule were 0.84 +/- .03 in the DS, and 0.81 +/- .06 in the VS. CONCLUSION: A clinical prediction rule using four easily measurable characteristics can identify individuals at high or low risk of nursing home residence 6 months after hip fracture.