Effect of a tailored behaviour change programme in highly educated adults: a randomised controlled trial

Abstract

Objectives. Little is known about the effectiveness and the adequate intervention dose of interventions to change multiple risk behaviours for cardiovascular disease. The aims of our study were to examine the effects and the dose-response effects of a tailored behaviour change programme on behaviour (diet, physical activity and smoking) in a highly educated study sample. Methods. A general sample of 314 highly educated adults was recruited in Belgium and allocated at random using a 2/3 ratio to an intensive intervention and a standard intervention. The participants that were allocated to the intensive intervention received medical assessments and could choose for behaviour change interventions (access to a tailored website, individual coaching and group sessions). Moreover, each participant in this study group could determine the dose (frequency and duration) and the delivery mode (e-mail, telephone, face-to-face) of his or her individual coaching at baseline. Participants in the standard intervention received medical assessments for data collection. The behavioural outcome measures were assessed with a validated fat intake questionnaire, the international physical activity questionnaire (IPAQ) and a national health questionnaire for smoking. Repeated measures analysis of variances were used to examine the differences between the study groups. Linear modelling was used to examine the dose-response effects for diet and physical activity. Results: Of the participants, 236 completed the questionnaires at baseline and after one year of intervention. Both the intensive intervention and the standard intervention resulted in a lower fat intake (p<.05) and a higher level of physical activity (p<.001). In the total sample, 23% of the smokers quitted smoking. No significant differences between the study groups were found for diet, physical activity and smoking. Independent of the motivation for behaviour change at baseline, significant dose-response effects were found for the intensive intervention. For diet, frequent telephone coaching should be combined with frequent face-to-face sessions to reduce the fat intake (p<.001). Intensive telephone coaching should be supplemented with frequent e-mails to increase physical activity (p<.05). Conclusions. No differences were found between the intensive intervention and the standard intervention. However, significant dose-response effects were found for the intensive intervention. The latter finding emphasizes the need to determine the adequate intervention dose and delivery mode to change behaviour in cardiovascular prevention programmes