October 25, 2007

Don't Fall for It

In an earlier posting, “Break a Leg,” I recommended that frail older people use hip protectors to prevent hip fractures. The data, at that time, were suggestive but not conclusive. A recent study, unfortunately, definitively argues against the benefits of hip pads. In an article published in the Journal of the American Medical Association, Dr. Douglas Kiel and his colleagues reported on a large randomized trial that used a very elegant approach to answer a difficult and important question (D Kiel, J Magaziner, S Zimmerman et al, “Efficacy of a Hip Protector to Prevent Hip Fracture in Nursing Home Residents,” Journal of the American Medical Association 2007; 298: 413-422).

Earlier studies were plagued by all sorts of problems: people didn’t like wearing the hip pads, leading to what was called “poor compliance,” making it hard to analyze the results. The hip pads studied were made of differing materials and some of the pads may actually have increased the chance that a fall would cause an injury to the hip bone itself rather than merely to the surrounding soft tissue. This new study used a hip protector that had been shown to have the desired biomechanical properties. It was conducted in nursing homes, where the frailest elders live, the people with the highest risk of falling and fracturing a hip. And the investigators did something very ingenious: they used each nursing home resident as his own control. Every individual in the study wore a one-sided hip pad on either the right or left hip. The researchers would then observe all the residents over time to see whether the protected hip was any less likely to be fractured than the unprotected hip.

The study was carried out in 1042 individuals with a mean age of 85 who lived in one of 37 nursing homes located in Massachusetts, Missouri, or Maryland. What the authors found was that the nursing home residents were just as likely to fracture the protected hip as the unprotected one. In fact, the study was stopped early because preliminary evidence was so overwhelming that the hip pads, contrary to everyone’s hopes and expectations, simply did not work. Even when the analysis was restricted to the 334 nursing home residents who wore the pad more than 80% of the time, there was still no difference in fracture rates between the protected and the unprotected hip.

It would have been great to be able to say, at last, that hip pads really work. But at least we now have the necessary information with which to conclude that they don’t. Now we know that we shouldn’t spend money on hip pads. I have to retract my earlier recommendation. It’s time to look for other strategies.

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