Process evaluation of a lifestyle intervention to prevent diabetes and cardiovascular diseases in primary care.

Effective, cost-effective, safe, and feasible interventions to improve lifestyle behavior in at-risk populations are needed in primary care. In the Hoorn Prevention Study, the authors implemented a theory-based lifestyle intervention in which trained practice nurses used an innovative combination of motivational interviewing (MI) and problem-solving treatment (PST). This article presents the intervention's reach, effectiveness in terms of process outcomes, adoption, and implementation. Recruitment strategy and participant flow were documented accurately. The effectiveness in terms of determinants of behavioral change was measured using a validated questionnaire. Questionnaires were also used to assess participant satisfaction and compliance, as well as practice nurses' confidence in providing the intervention. Counseling sessions were tape recorded to assess MI, PST, and general counseling competence. The findings indicate that the recruitment strategy was adequate and resulted in a reasonably extensive reach of the target population. Practice nurses were competent and confident in their provision of MI and PST, and participant satisfaction was high. Nevertheless, the number of sessions attended was low, and almost no effects were seen on determinants of behavioral change. The authors conclude that implementing this type of intervention in primary care is feasible, but more is needed to effectively facilitate changes in determinants of lifestyle behavior in this population.