Hip protector does not reduce fracture risk among nursing home residents

Investigators terminated the study due to a lack of effectiveness after 20 months of follow-up.

Using an energy-absorbing hip protector provides no protection against hip fracture for nursing home residents, according to a study published in the Journal of the American Medical Association. The study results add to increasing evidence that such protectors, as currently designed, are not effective for preventing hip fractures, the authors noted.

Douglas P. Kiel, MD, MPH, of Hebrew SeniorLife and Harvard Medical School, Boston, and colleagues conducted a randomized, controlled trial from October 2002 to October 2004 to evaluate the effectiveness of an energy-absorbing and energy-dispersing hip protector in reducing the incidence of hip fracture among nursing home residents.

The study included 1,042 nursing home residents at 37 centers. Participants averaged 85 years of age, and 79% were women.

Each participant wore a hip protector on one hip only for an average of 7.8 months, with a 73.8% overall adherence rate. Each participant's contralateral hip served as their own control, according to the study.

The hip protector used consisted of a 0.32-cm outer layer of 2.7 kg/m³ polyethylene, which was backed by a hard high-density 0.95-cm polyethylene shield. This shield was backed by 0.9 kg/m³ of 1.27-kg ethylene vinyl acetate foam, according to the study.

After a 20-month follow-up, investigators terminated the study due to a lack of effectiveness.

They found a 3.1% incidence rate of hip fracture on protected hips, which did not significantly differ from the 2.5% incidence rate for unprotected hips. Similarly, in an analysis of 334 residents with more than 80% adherence to the study protocol, the researchers found a 5.3% incidence of hip fracture on protected hips, which was also not significantly different from the 3.5% fracture incidence for unprotected hips.

"In summary, this large multicenter clinical trial failed to demonstrate a protective effect of a hip protector on hip fracture incidence in nursing home residents despite high adherence, confirming the growing body of evidence that hip protectors are not effective in nursing home populations," the authors wrote.

"With the development of better pad materials and more thorough testing, future studies should examine new hip protectors using nonclustered randomized designs like ours to avoid many methodological biases," they wrote.

For more information:
Kiel DP, Magaziner J, Zimmerman S, et al. Efficacy of a hip protector to prevent hip fracture in nursing home residents. JAMA. 2007;298:413-422.