Cognitive Status at Hospital Admission: Postoperative Trajectory of Functional Recovery for Hip Fracture

Cognitive impairment is common in the hip fracture patient population, yet few studies of functional recovery include this subgroup. The objective was to determine whether baseline cognition was a determinant of the rate of functional recovery over 6 months after hip fracture.

A consecutive cohort of 383 patients 65 years or older who were treated for hip fracture within a Canadian health region were grouped on cognitive status. Participants with Mini-Mental Status Examination scores <18 at 3-5 days postoperatively were classified as cognitively impaired. Primary outcome was the Functional Independence Measure. Interviews were completed within 5 days postoperatively (baseline), 1, 3, and 6 months postoperatively. Linear mixed modeling examined the pattern of recovery and the effect of cognitive status.

Of the 383 participants, 104 (27%) had Mini-Mental Status Examination scores of less than 18. The effect size for changes in the FIM over 6 months was large for those without cognitive impairment (effect size = 2.3) and smaller for those with cognitive impairment (effect size = 0.9). After adjusting for age, gender, proxy respondent, and fracture type, participants with impaired cognition recovered more slowly, never attaining comparable levels with those without cognitive impairment. The 6-month health status for the cohort was substantially lower than the health status of age-gender-matched, community-dwelling adults.

Patients with cognitive impairment who fracture their hips recover more slowly and achieve less functional recovery. Recovery is not uniform nor is it linear over the initial 6 months. The diversity of patient needs should be recognized postoperatively so that long-term recovery is optimized.