Impact of Intervention Dose on Cancer-Related Health Behaviors among Working-Class, Multiethnic, Community Health Center Patients

Abstract

To examine the relationship between intervention dose and health behavior change in Healthy Directions-Health Centers, an intervention designed to reduce cancer risk factors. DESIGN. Analysis of intervention condition participant data from a randomized controlled trial. Community health centers in Massachusetts. Patients residing in low-income, working-class, multiethnic neighborhoods. Components were clinician endorsement, in-person counseling session and four telephone counseling sessions with a trained health advisor, and social-contextual tailored materials. Intervention dose was number of six possible intervention components completed by each participant. Changes in fruit and vegetable consumption, red meat consumption, physical activity, and multivitamin intake between baseline (n=1088) and 8-month follow-up (n=967; 89% of baseline sample) were determined. Bivariate and multivariate associations between intervention dose and change in health behaviors were examined. In multivariate analysis, the association between intervention dose and increase in multivitamin intake approached significance (p < .07). Seventy percent of participants completed all intervention activities. In bivariate analysis, completion of four telephone counseling calls was associated with decrease in red meat consumption (p < .05). These findings indicate that future studies should examine the number, content, and length of contacts needed for behavior change. The results also suggest that health centers are a channel for reaching diverse populations, as shown by the high level of intervention implementation.