External hip protectors are effective for the elderly with higher-than-average risk factors for hip fractures

Abstract

In our cluster randomised controlled trial for efficacy of hip protector with 672 ambulatory elderly women, a hip protector was more effective for prevention of hip fractures in residents with fall history (n = 202; hazard ratio (HR), 0.375; 95%CI, 0.14-0.98; p = 0.05) and body-mass index (BMI) < or = 19.0 (n = 206; HR, 0.37; 95%CI, 0.14-0.95; p = 0.04) by a Cox proportional hazards regression model. Hip fractures result from both osteoporosis and falling. A potentially cost-effective method of preventing hip fractures involves the use of hip protectors but recent studies have revealed the uncertain effectiveness of hip protectors even in institutional settings. This study was a cluster randomised controlled trial with nursing homes. We randomly assigned 76 homes with 672 ambulatory but frail elderly women. Several risk factors were assessed at baseline and incorporated into a Cox proportional hazards regression model. UMIN Clinical Trials Registry number is UMIN000000467. Research period was between January 2004 and March 2006. In the intervention group, 19 hip fractures occurred (54.0/1,000 person-years), whereas 39 hip fractures occurred in the control group (78.8/1,000 person-years). Hazard ratio of hip fracture in the intervention group was 0.56 (95%CI, 0.31-1.03; p = 0.06) after adjusting for risk factors. In subgroup analysis, hip protectors were more effective for prevention of hip fractures in residents with fall history (n = 202; HR, 0.375; 95%CI, 0.14-0.98; p = 0.05) and BMI < or = 19.0 (n = 206; HR, 0.37; 95%CI, 0.14-0.95; p = 0.04). Overall compliance with use of hip protectors was 79.7%. Risk of hip fracture can be reduced by hip protectors among elderly women with fall history and low BMI.