Know your numbers: comparing participants and nonparticipants in a university health screening program.

University faculty and staff members were offered the opportunity to participate in a worksite health screening program. Both the participants and the nonparticipants responded to a questionnaire concerning their dietary and health practices. Participants' values for total serum cholesterol, blood pressure, and percentage of body fat were measured. No significant differences between the two groups were observed for the parameters of self-reported total serum cholesterol or blood pressure, and the participants' self-reported and measured serum cholesterol values were not significantly different from those of the nonparticipants. However, the measured and self-reported percentages of body fat of participants were significantly different from reported percentages of body fat of those who did not participate. Further exploration of the motivation of participants in health screening programs is called for.