Background: Few studies have examined the relationship between inpatient bed rest and functional outcomes. We examined how immobility is associated with function and mortality in patients with hip fracture.
Methods: We conducted a prospective cohort study of 532 patients 50 years and older, who were treated with surgery after hip fracture in 4 hospitals in New York. We collected information from hospital visits, medical records, and interviews. "Days of immobility" was defined as days until the patient moved out of bed beyond a chair. Follow-up was obtained on function (using the Functional Independence Measure) at 2 and 6 months and on survival at 6 months.
Results: Patients with hip fracture experienced an average of 5.2 days of immobility. Compared with patients with a longer duration of immobility (ie, at the 90th percentile) in adjusted analyses, patients at the 10th percentile of immobility had lower 6-month mortality (-5.4%; 95% confidence interval [CI], -10.9% to -1.0%) and better Functional Independence Measure score for locomotion (0.99 points; 95% CI, 0.3 to 1.7 points, with higher values indicating better function), but there was no significant difference in locomotion by 6 months (0.58 points; 95% CI, -0.3 to 1.4 points). The adverse association of immobility was strongest in patients using personal assistance or supervision with locomotion at baseline (difference in 6-month mortality between the 90th and 10th percentile of immobility was -17.1% [P = .004] for this group and only 1.2% [P = .38] for patients independent in locomotion at baseline).
Conclusion: In patients with hip fracture, delay in getting the patient out of bed is associated with poor function at 2 months and worsened 6-month survival.