Reach and engagement in the ECAIL trial targeting socially disadvantaged families across the COVID-19 pandemic and cost-of-living crisis: A mixed-methods implementation study

The ECAIL trial, launched in 2017, was designed to evaluate a multicomponent intervention for childhood obesity prevention among hard-to-reach families. At a maternity hospital in Lille, France, healthcare providers screened pregnant women experiencing social vulnerability, and dietitians delivered a home-based intervention until age 2. The COVID-19 pandemic led to a six-month suspension in 2020. This study compared eligibility and participation before the pandemic and after resumption, and examined how implementation and reach evolved across the pandemic and subsequent cost-of-living crisis.

Using a convergent mixed-methods design, we analyzed 5,744 eligibility questionnaires distributed at the maternity ward and conducted a focus group with six dieticians delivering the intervention to triangulate quantitative implementation indicators with qualitative implementation data. Inclusion criteria included ≥1 indicator of social vulnerability (e.g., socioeconomic disadvantage, precarious housing, or social isolation). The focus group was recorded, transcribed, and analyzed thematically focusing on reach, acceptability, and adaptation.