A randomized controlled trial of nutrition education to promote farmers’ market fruit and vegetable purchases and consumption among women enrolled in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC): rationale and design of the WIC Fresh Start program

Abstract

This report describes the protocol guiding the design and evaluation of a theory-driven, web-based lesson to promote farmers’ market fruit and vegetable (FV) purchases and consumption among women enrolled in the Special Supplemental Nutrition Program for Women, Infants and Children (WIC). Designed to leverage vouchers provided to WIC participants for FV purchases through the Farmers’ Market Nutrition Program (FMNP) and monthly cash value vouchers (CVVs) redeemable at farmers’ markets, the lesson is conceptually grounded in formative research on knowledge, attitudes and skills influencing farmers’ market FV purchases and consumption and theoretical understanding of approaches for modifying them. The setting is a large WIC agency serving three New Jersey counties. Separate samples of women were recruited to participate in 1) focus groups for guiding lesson content development (N = 56) and pretesting the resulting content (N = 52), 2) cognitive testing to assess the clarity and interpretability of items and response formats in measures of knowledge, attitudes and skills developed for the study (N = 15), 3) one-on-one sessions to assess reactions to initial versions of video segments developed for the lesson (N = 20), and 4) the outcome evaluation (N = 744). Stratified based on FMNP voucher receipt, participants are randomized to receive the lesson or existing online health education. Outcome measures (administered orally to reduce literacy demands of the response task) are completed at pretest (immediately before the lesson), posttest (2 weeks after the lesson), and 3 and 6 months after posttesting. Short- and long-term lesson effects on FV intake, FMNP voucher redemption and the redemption of CVVs at farmers’ markets will be evaluated. Evidence for mediation by knowledge, attitudes and skills of lesson effects on FV intake and voucher redemption, dose-response relationships, and user satisfaction with the lesson also will be examined. Theory-driven, web-based nutrition education expressly designed for WIC to promote farmers’ market use is lacking. The WIC Fresh Start program addresses the paucity of programs of this type. Findings will advance understanding of effective approaches for promoting farmers’ market FV purchases and consumption among WIC participants. NCT02565706 (registered September 30, 2015)