Survival of participating and nonparticipating limb amputees in prospective study: consequences for research.

This study quantified selection by analyzing the survival rate of the participants and nonparticipants in a 4-year prospective, multicenter cohort study. In addition, the differences between these groups were analyzed. Surgeons of six hospitals in the northern Netherlands referred, in total, 225 patients to the study. Of these patients, 60% (n = 134) participated in the prospective study by filling in questionnaires; the others (nonparticipants) were followed over time through their records. No significant differences were found in sex and level of amputation between participants and nonparticipants; however, of the two groups, nonparticipants were significantly older. Reason for amputation was peripheral vascular disease (PVD) for 67% (n = 90) of the participants and 82% (n = 75) of the nonparticipants. The mean survival time of the participants and nonparticipants was 36.1 and 29.6 months, respectively. Within PVD, the mean survival time of participants and nonparticipants was 34.4 and 27.6 months, respectively.To summarize, our article gives an overview of the survival rates in a prospective study on patients scheduled for a limb amputation. Our study sample was biased by selection and death. Participants were generally healthier than nonparticipants.