Formative research implications on design of a randomized controlled trial for oral health promotion in children

BACKGROUND: The COordinated Oral health Promotion (CO-OP) Chicago trial will test the efficacy of a community health worker (CHW) intervention to improve oral health behaviors for children at high risk for early childhood caries. Before implementing the cluster-randomized controlled trial, we conducted a formative assessment to determine the final design. We used qualitative methods to assess the feasibility and acceptability of the proposed recruitment, data collection, and intervention plan. METHODS: Key informant interviews (N = 37) and site observations were conducted at 10 pediatric primary care clinics and 10 Special Supplemental Nutrition Program for Women Infant and Children (WIC) centers to gain insight from providers and administrators at the locations where recruitment and intervention will occur. Eight focus groups (N = 68) were conducted with caregivers of children to capture the parent perspective. Conceptual coding methods from grounded theory were applied to organize the data into the final themes. RESULTS: Families, clinics, and WIC centers were all very interested in additional supports for oral health and were enthusiastic about CHWs. Challenges included competing family priorities that might interfere in study enrollment and intervention efficacy. Physical space for enrollment and intervention delivery was a major barrier for some sites. Home visits for data collection and intervention delivery would be unacceptable for some families. These challenges and barriers prompted us to make major changes in our trial design. We opened the option for data collection to occur in multiple locations. We eliminated the home-only arm of the trial. Clinics and WIC centers that are randomized to the non-intervention arm will now have CHWs available at the study conclusion. Finally, we aligned the CHW oral health topics to the needs of families. CONCLUSIONS: We conducted this comprehensive formative assessment to determine the feasibility and acceptability of the CO-OP Chicago trial. While overall acceptance of the trial was high, the results highlighted specific issues with the proposed trial implementation plan and led to several critical design changes. This type of formative work requires a significant upfront investment but we expect it will translate into savings through better recruitment, retention, intervention implementation and adherence, and result dissemination. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s40814-018-0344-y) contains supplementary material, which is available to authorized users.