RE-AIM: Researchers

RE-AIM Framework:
Reach of Health Behavior Interventions

Definition: The absolute number, proportion, and representativeness of individuals who are willing to participate in a given initiative

Research Issue:

Are we giving enough consideration to representation in our studies?

Most health promotion intervention studies report the size of the study sample and the proportion of individuals who are willing to participate. The proportion is operationalized as participation rate, which is calculated as those who participate divided by the total number of eligible individuals.
In contrast, few studies report the representativeness of the study sample. Representativeness is defined as the similarity or differences between those who participate and those who are eligible but do not. If differences do exist, a given intervention may have a differential impact based upon these variables that cannot be determined due to the lack of representativeness of the sample. If differences do not exist, then a stronger case for the generalization of the intervention into real-world settings may be made. Comparisons should be made on basic demographic characteristics and, when possible, on primary outcomes.

Examples of Reach from recent literature:

Eakin and her associates (1998) illustrate how Reach issues can be incorporated in a smoking cessation study offered to participants in a planned-parenthood program. They begin by explicitly reporting their exclusion criteria --female smokers between 15 and 35 years of age who are patients at a planned-parenthood clinic. During a routine visit to the clinic the patient services staff described the study and solicited participants. Those women who declined (n=185) were asked to complete a short questionnaire that included questions to assess demographics, smoking rate, and reasons for non-participation. Participants (n=518) also completed baseline demographic and smoking rate assessments. They tracked recruitment efforts and reported that 74% percent of the women approached agreed to participate in the study. To determine the representativeness of the sample two procedures were completed. First, based on information from patient medical charts, those who were contacted were compared on personal demographics to those who were not contacted. Second, participants were compared to non-participants on personal demographics and smoking rate. The study found that those contacted did not differ from those not contacted on any of the test variables. Also, the results suggested that participants were slightly younger than non-participants, but there were no other differences between these groups. This suggests that Eakin and her associates were fairly successful in contacting and recruiting a fairly representative sample of their target population.
The Language for Health (Elder et al., 2000) nutrition education intervention provides a good example of determining the representativeness of study participants to a given target population. The behavior change intervention was developed to target Latino participants in English as a second language (ESL)classes at seven schools. To examine representativeness, the 710 participants in the study were compared to the overall Latino ESL student population in the city. This comparison revealed that the intervention participants did not differ from the general ESL student population on gender, age, or education level. As such, the authors concluded that the study had strong generalizability to the greater target population (Elder et al., 2000).