A Cluster-Randomized Trial of a Mobile Produce Market Program in 12 Communities in North Carolina: Program Development, Methods, and Baseline Characteristics

Abstract

Background: Mobile markets are an increasingly popular method for providing access to fresh fruits and vegetables (F/V) in underserved communities; however, evaluation of these programs is limited, as are descriptions of their development, study designs, and needs of the populations they serve.

Objective: Our aim was to describe the development and theoretical basis for Veggie Van (VV), a mobile produce market intervention, the study design for the VV evaluation, and baseline characteristics of the study population.

Design: The protocol and sample for a cluster-randomized controlled trial with 12 sites are described.

Participants/setting: Community partner organizations in the Triangle region of North Carolina that primarily served lower-income families or were located in areas that had limited access to fresh produce were recruited. Eligible individuals at each site (older than 18 years of age, self-identified as the main shoppers for their household, and expressed interest in using a mobile market) were targeted for enrollment. A total of 201 participants at 12 sites participated in the VV program and evaluation, which was implemented from November 2013 to March 2016.

Main outcome measures: Change in F/V intake (cups/day), derived from self-reported responses to the National Cancer Institute F/V screener, was the main outcome measure.

Statistical analyses performed: We performed a descriptive analysis of baseline sample characteristics.

Results: Mean reported F/V intake was 3.4 cups/day. Participants reported generally having some access to fresh F/V, and 57.7% agreed they could afford enough F/V to feed their family. The most frequently cited barriers were cost (55.7%) and time to prepare F/V (20.4%). Self-efficacy was lowest for buying more F/V than usual and trying new vegetables.

Conclusions: By addressing cost and convenience and building skills for purchasing and preparing F/V, the VV has the potential to improve F/V consumption in underserved communities.

Keywords: Cluster-randomized trial; Food environment; Fruits and vegetables; Lower-income; Mobile market.