In order to prevent hip fractures 548 fall-prone senior citizens living in 20 nursing homes participated in a randomized controlled trial of hip protectors. One hundred and sixty-four were randomly selected into the control group and 384 into the intervention group. Of the patients in the intervention group 138 (35.9%) wore the protector throughout the whole 10 months of the study's duration, 124 (32.3%) quit wearing the protectors after an initial wearing period and 122 (31.8%) refused to wear them at all. The regular wearers had the protector on during an average of roughly 12 hours a day, so they were protected for 50% of their exposure time (including at night). Fifty-nine percent of the drop-outs stopped wearing the protectors in the first two study months, mostly for non-medical reasons. Calculation by a forecasting model showed that those senior citizens who were initially prepared to wear the protector tended to be those who were physically restricted.