Who participates in research on adherence to treatment in insulin- dependent diabetes mellitus? Implications and recommendations for research

OBJECTIVE: Examine the implications of nonparticipation in studies of treatment adherence among adolescents with chronic health conditions. METHODS: Empirical data from an adherence study with adolescents with diabetes were used to demonstrate the influence of family participation on demographic and health outcome variables. Ninety-four families were categorized into one of three groups: (1) families that declined to participate in the study at recruitment (nonconsenters), (2) families that agreed to participate, but failed to return the study questionnaires (nonreturners), and (3) families that had at least one family member return the questionnaires (participants). RESULTS: Despite being similar demographically, nonreturners had significantly lower treatment adherence scores and the adolescents tested their blood sugar less frequently than participants. Participants and non-consenters did not differ on any available data. CONCLUSIONS: We discuss the implications of these group differences on the generalizability of research findings, offer suggestions about how to maximize and maintain participation in research studies, and suggest directions for future research.