Patients with hip fracture: subgroups and their outcomes.

OBJECTIVES: To present several alternative approaches to describing the range and functional outcomes of patients with hip fracture.
DESIGN: Prospective study with concurrent medical records data collection and patient and proxy interviews at the time of hospitalization and 6 months later.
SETTING: Four hospitals in the New York metropolitan area. PARTICIPANTS: Five hundred seventy-one hospitalized adults aged 50 and older with hip fracture between July 1997 and August 1998. MEASUREMENTS: Rates of return to function in four physical domains, mortality, and nursing home residence at 6 months. Cluster analysis was used to describe the heterogeneity among the sample and identify variations in 6-month mortality, nursing home residence, and level of functioning and to develop a patient classification tree with associated patient outcomes at 6 months postfracture.
RESULTS: In locomotion, transfers, and self-care, 33% to 37% of patients returned to their prior level of function by 6 months, including those needing assistance, but only 24% were independent in locomotion at 6 months. Cluster analysis identified eight patient subgroups that had distinct baseline features and variable outcomes at 6 months. The patient classification tree used four variables: atypical functional status (independent in locomotion but dependent in other domains); nursing home residence; independence/dependence in self-care; and age younger than 85 or 85 and older that identified five subgroups with variable 6-month outcomes that clinicians may use to predict likely outcomes for their patients.
CONCLUSION: Patients with hip fracture are heterogeneous with respect to baseline and outcome characteristics. Clinicians may be better able to give patients and caregivers information on expected outcomes based on presenting characteristics used in the classification tree.