The importance of matching the evaluation population to the intervention population: Using Medicaid data to reach hard-to-reach intervention populations

Abstract

Subject recruitment is a challenge for researchers and evaluators, particularly with populations that are traditionally hard to reach and involve in research, such as low-income and minority groups. However, when the evaluation sample does not reflect a program's intended audience, the discrepancy may lead to evaluation results that are not valid for that audience. We conducted evaluation activities for a state Supplemental Nutrition Assistance Program-Education (SNAP-Ed) intervention that promotes consumption of fruits and vegetables (F&V) in low-income areas. Previous program evaluations efforts had failed to obtain a sufficient proportion of individuals identified as low-income based on their participation in SNAP. We used state Medicaid data as a means of identifying low-income families to recruit for a telephone survey (n=311) and an in-depth qualitative interview (n=30) that we designed for the program being evaluated. We chose to focus on the dynamics of parent-child communication around F&V because we considered this previously unevaluated component of the intervention vital to understanding program effectiveness. Our results indicated that the Medicaid database provided an appropriate sample and that parents reported frequent F&V requests from their children. Parents also reported that they would positively respond to requests in many different settings, such as grocery stores (92.6%), restaurants (88.1%), and fast food restaurants (80.4%).

Keywords: Evaluation; Nutrition; Sample; School-aged children.