Most functional outcomes are similar for men and women after hip fracture: a secondary analysis of the enhancing mobility after hip fracture trial

BACKGROUND The impact of gender on functional outcomes after hip fracture is not known. We aimed to determine the extent to which gender influenced functional outcome and response to exercise in older people after hip fracture, and to determine if any differences persisted after adjusting for cognition, weight and age. METHOD Secondary analysis of data from the Enhancing Mobility After Hip Fracture trial in which older people after hip fracture received either a lower or higher intensity exercise program. Functional outcomes included physical performance and self-reported measures. Regression models were used to compare genders at baseline, week 4 and week 16, with adjustment for baseline values, cognition, weight and age. Interaction terms were used to assess a differential impact of the intervention by gender. RESULTS Outcome data were available for 160 participants, 30 men (19%) and 130 women (81%) at baseline, with the withdrawal of 4 men (13%) and 6 women (5%) at week 16. There were no gender differences for any baseline measures or for most of the 19 functional outcome measures at weeks 4 and 16. At week 4 men performed better in knee extensor strength (2.1 kg, 95% CI 0.6 to 3.7, p < 0.01). This difference did not persist after adjustment for body weight, however persisted after adjusting for baseline, cognition, and age (p = 0.038). At week 4, men performed better in coordinated stability (-10.0 error score, 95% CI -17.6 to -2.4, p=0.010) and this persisted after adjusting for baseline values only but not for cognition and age (p = 0.073). At week 16, men performed better in coordinated stability (-10.2 error score, 95% CI -18.4 to -1.9, p=0.016) and this persisted after adjusting only for cognitive impairment (p = 0.029) but not for age and baseline (p = 0.135). There was no indication of a differential impact of intervention type on the basis of gender. CONCLUSIONS A few between gender differences were observed in strength and balance, however these appeared to be confounded by body weight, age and/or cognition.