Modifiable and non-modifiable risk factors affecting walking recovery after hip fracture

Summary: Modifiable and non-modifiable predictors of mobility recovery were analyzed on a sample of 774 hip fracture patients according to pre-fracture abilities. Overall predictors were mostly non-modifiable factors related to frailty of patients with the exception of 25-hydroxyvitamin D concentration which significantly affected walking recovery, especially in patients with higher pre-fracture performance. Introduction: This study aims to investigate mobility changes after hip fracture with the aim of identifying modifiable and non-modifiable predictors of mobility recovery according to different pre-fracture abilities. Methods: This is a prospective inception cohort study of consecutive older patients, admitted with a fragility hip fracture in three Hospitals of Emilia Romagna (Italy). A sample of 774 patients alive at the sixth month was divided into three groups according to pre-fracture ambulation ability (group 1: mobile outdoors; group 2: mobile indoors; and group 3: mobile with help). The relationship between baseline characteristics of patients and the odds of walking recovery was analyzed using multivariate regression analysis. Results: Mortality differed significantly among the three groups and was the highest in patients needing help to walk. Among the survivors, only 50.3 % of patients recovered walking ability. In a multivariate analysis, independent risk factors were different among the three groups. In group 1, older age, comorbidities, the use of walking devices before fracture, and low albumin level acted as negative factors while male gender, a pre-fracture high functional status, and higher 25-hydroxyvitamin D levels increased the probability of full recovery. In group 2, only pre-fracture functional status and 25-hydroxyvitamin D concentration were related to the recovery of walking ability. Pre-fracture functional status was also the only significant predictor for patients in group 3. Conclusions: Several baseline characteristics of patients are related to the likelihood of recovering walking ability after hip fracture. The 25-hydroxyvitamin D level seems to be the only relevant modifiable factor even if the effectiveness of its supplementation has yet to be demonstrated.