Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
To the Editor: The negative results in the
study by Ms van Schoor and colleagues1 underscore
the importance of adherence in measuring the effectiveness of hip protectors.
Although the authors extended the follow-up duration to address the
inadequate number of study participants, a larger issue arises from the authors'
ambitious risk reduction estimate of 75% that they used to compute the power
of their study. Such a risk reduction exceeds that reported in the largest
trials to date, and results from these studies also had wide confidence intervals.2- 4 Such studies
generally have found that external hip protectors reduce the risk of fracture,
but that poor adherence undermines their effectiveness. It is not clear that
the measure of compliance in this study was comparable with that of other
studies, and both recall bias and provision of socially acceptable responses
may have overestimated true compliance in those who fell.
Honkanen LA. External Hip Protectors and Risk of Hip FractureExternal Hip Protectors and Risk of Hip Fracture. JAMA. 2003;290(7):883. doi:10.1001/jama.290.7.883-a