Process evaluation of a clinical preventive nutrition intervention

Background. We report process data on the feasibility of delivering a clini cal preventive nutrition intervention that was effective in increasing part icipants' consumption of fruits and vegetables. We also examine relationshi ps between process variables and study outcomes. Methods. We randomly assigned six practice sites in a managed care organiza tion to a dietary intervention or control condition. We invited adults 18 y ears of age or older scheduled for routine health visits within the subsequ ent 2 months to participate. Of the 566 patients we contacted from the inte rvention sites, 230 (41%) enrolled. From the control sites, we contacted 61 7, and 274 (44%) enrolled. Intervention participants received a tailored le tter providing feedback on their consumption of target foods together with recommendations for improvement, stage-matched nutrition education booklets , a diet-health endorsement from their primary care providers (PCPs), and t wo motivational counseling telephone calls. Of enrollees, 195 (85%) in the intervention group and 252 (92%) in the control group returned the final su rvey 3 months later. Results. Seventy-one percent of both participants and PCPs reported that th e PCPs had discussed the relationship between diet and health at their visi t. Fifty-seven percent of participants and 62% of PCPs reported that they d iscussed the complete diet-health endorsement, which included: (1) acknowle dgment of the relationship between diet and health and (2) tailored study r ecommendations. The inclusion of both parts of the diet-health endorsement, but not the length of time spent, appeared to correlate with healthful out comes. Conclusions. These process data suggest that the brief PCP diet-health endo rsement contributed to the intervention effect on fruits and vegetables. (C ) 2001 American Health Foundation and Academic Press.