Recruitment and retention of WIC participants in a longitudinal dietary intervention trial

This paper describes strategies and outcomes of techniques to recruit and retain low-income women served by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in a longitudinal dietary intervention trial.

Community engagement strategies, methods to recruit and retain participants, and recruitment and retention rates are reported. Demographic and lifestyle predictors of loss to follow-up, contacts required to reach participants at each data collection point, participant reactions to the recruitment and retention strategies used, and reasons for drop out (assessed among those who discontinued their study involvement) also were examined.

Of 1281 eligible women, 744 were enrolled (58% recruitment rate); retention rates were 87%, 70%, and 55%, respectively, 2 weeks and 3 and 6 months post-intervention. Being unmarried, younger, and having low baseline vegetable intake predicted loss to follow-up. Between 4 and 5 contact attempts and 1 and 2 completed contacts were required to reach participants at each data collection point. Participants endorsed recruiting women while waiting for WIC appointments (as they were accessible, perceived the information provided as informative, and wanted to pass the time) and by word of mouth. Lacking time and loss of interest were commonly reported reasons for not completing assessments and dropout. To improve retention, shortening telephone assessments, conducting the assessments in person, and increasing the amount of incentives were recommended.

Despite using recommended strategies, recruitment and retention rates were modest. Research is needed to identify and test approaches to effectively engage WIC-enrolled adults in health intervention trials.