Rate of Mortality with Hip Fracture and its Prognostic Factors in an elderly Japanese population

ABSTRACT

The purpose of this study was to clarify the survival rates and prognostic factors in elderly Japanese patients with hip fractures. This study investigated the outcome of 256 patients aged 60 years and older with surgically treated hip fractures. Information including age, gender, duration of hospitalization, place of residence before fracture and at discharge, and level of mobility before fracture and at discharge was obtained from patient records. The survival of the patients after discharge was determined by mail surveys supplemented with telephone inquiries.The observed survival rates were significantly lower than the expected survival rates (p<0.001, by Mantel Haenszel test). The short-term mortality rates were 6% for six months and 12.7% for one year, which were lower than previously reported rates in Western countries. Significantly higher hazard ratios (HR) for mortality adjusted for age and gender were observed in patients who had lived in places other than their own home before fracture (HR=2.67(1.63-4.3)), were discharged to places other than their own home (Nursing home HR=2.25 (1.24-4.1) or to a non-orthopedic unit (HR=5.95 (3.12-11.34)), those requiring full-time assistance for mobility at discharge (HR=5.71 (3.59-9.01)), and those who had stayed in a hospital for fewer than 40 days (HR=2.20 (1.38-3.51)). After adjusting for the effects of all the potential prognostic factors, discharge to places other than their own home and the lowest level of mobility at discharge remained significant factors causing adverse effects on survival.Therefore, to improve the prognosis, patients should be allowed to recover to a level at which they can ambulate with some assistance, enabling them return to their own homes.