Outcome assessment in hip fracture: evaluation of the practicality of commonly-used outcomes in hip fracture studies.

INTRODUCTION

Elderly patients are at a major risk for a first hip fracture. The decrease in bone mineral density may account for 60-85% of the variability in fracture risk. Other contributing factors for hip fractures include cognitive impairment as well as impaired mobility and visual depth perception. Dizziness and poor or fair self-perceived health care characteristics are predictive of a second hip fracture. In general, patients over the age of 65 years admitted to a geriatric rehabilitation unit after proximal hip fracture have complex multiple interacting pathologies with 78% having significant co-morbidity. Because of the added co-morbidity, we believed that the choice of outcome assessment in hip fracture studies would reflect the practical qualities of an instrument. The purpose of our study was to evaluate the practicality of functional outcome instruments found in the current literature in the elderly following postoperative hip fracture.

METHODS

We coded the instruments according to the International Classification of Functioning, Disability and Health conceptual framework. 24 different instruments measuring Body Function, 13 instruments evaluating Activity and Participation and 8 composite scores were identified. Practicality was evaluated using four dimensions: respondent burden, examiner burden, score distribution and format compatibility.

RESULTS

All instruments evaluating Body Function were performance-based and used exclusively in rehabilitation trials. Performance-based instruments also correlated with a high score in examiner and respondent burden. Surgical trials mostly adopted the Harris hip score which was rated low in examiner and respondent burden. The SF-36 was rated with an adequate score distribution but low in format compatibility.

DISCUSSION AND CONCLUSION

An instrument with low respondent burden and minimal examiner burden demonstrated better potential for being applicable in randomized trials with elderly hip fracture patients presenting with co-morbidities. In the future we believe that practical qualities should also be considered when developing or utilizing instruments.