Characteristics of participating and nonparticipating men in a randomized, controlled diet and exercise intervention trial

Abstract

Objective: To study characteristics of importance for participation in a diet and physical exercise prevention programme.

Setting: Primary Health Care, Sollentuna, and the Karolinska Hospital, Stockholm, Sweden.

Subjects: A sample of 187 men, aged 35-60, with increased risk factors for CHD, were invited to a 6-month prevention programme. Participants (n = 158) were randomized into a diet group, a physical exercise group, a diet and physical exercise group, and a control group. Twenty-seven men, who declined participation, formed the group of nonparticipants.

Design: Participants and nonparticipants were compared with respect to health beliefs, health knowledge, CHD risk factors, demographic and personality factors.

Main outcome measures: Characteristics of men participating and not participating in the intervention trial.

Results: Nonparticipants, compared with participants, believed less in the benefits of dietary change and perceived the health threat of stroke and myocardial infarction as less serious. Nonparticipants had a better knowledge of a number of risk factors for cardiovascular disease.

Conclusion: Belief in treatment efficacy and perceived health threat, rather than health knowledge, predicted initial participation in a non-pharmacological intervention trial.