Changes in short-term cognitive function following a hip fracture in the elderly and the effect of cognitive function on early post-operative function.
Keywords:hip fracture, elderly, cognitive function, early post-operative functional outcome, Six-Item Cognitive Impairment Test
OBJECTIVE: To evaluate the changes in short-term cognitive function and the relation between cognition and early post-operative functional outcome in the elderly following a hip fracture
DESIGN: Prospective pre-test-post-test observational study
SETTING: Two public hospitals in Johannesburg, South Africa
PARTICIPANTS: Ninety elderly patients with a first time unilateral hip fracture over the age of 60 years were consecutively sampled. Patients with polytrauma and those with co-morbidities affecting mobility (stroke, Parkinson's disease or a spinal cord injury) were excluded. Patients re-admitted with complications of a previous surgery or those managed conservatively were also excluded. Seventy-two participants completed the study
DATA COLLECTION: Pre-operative (baseline), discharge and six weeks post discharge assessments were carried out. Cognitive function was established using the Six-Item Cognitive Impairment Test (6CIT) at each of the three assessment periods. The participants' post-operative functional level was assessed using the Elderly Mobility Scale (EMS) and the Lower Extremity Functional Scale (LEFS) at discharge and at six weeks post discharge RESULTS: This study revealed significant advances in cognition from baseline to six weeks post discharge (z-statistic -5.04, p=0.000). After adjusting for pre-fracture functional mobility and pre-existing co-morbidities, a multivariate regression analysis revealed that cognitive function is also a strong predictor of early post-operative functional outcome (β= -0.14, p=0.036
CONCLUSION: Cognitive function in elderly individuals with a hip fracture does improve over time. Cognitive function is a strong predictor of early post-operative functional outcome, when adjusted for pre-fracture functional mobility and pre-existing co-morbidities