Sustaining reach and engagement in the ECAIL trial during health and cost-of-living crises
How can public health interventions be sustained among families experiencing social disadvantage during major crises?
A new PLOS ONE publication addresses this question using data from the ECAIL trial (prEgnanCy and eArly Childhood nutrItion triaL). Launched in 2017 in northern France, ECAIL evaluates a multicomponent intervention for childhood obesity prevention, from pregnancy to age 2, in partnership with Programme Malin.
The COVID-19 pandemic interrupted recruitment and home visits in March 2020, before activities gradually resumed under adapted procedures. It was followed by inflation and the cost-of-living crisis, potentially intensifying challenges faced by families. The study therefore examined how ECAIL implementation and reach evolved across these changing contexts.
A mixed-methods approach combined quantitative data from the Lille site (5,744 eligibility questionnaires and indicators of recruitment, participation and follow-up) with the experiences of six dietitians collected during a focus group.
The proportion of pregnant women eligible for the trial increased from 29.7% before the pandemic to 33.6% after activities resumed, reflecting a more challenging socioeconomic context. Despite successive crises, participation remained broadly stable, at around 25%. Qualitative findings highlighted the importance of rapidly resuming home visits, which were particularly valued in a context of social isolation. Pre-visit telephone calls, initially introduced during the pandemic, were also associated with fewer unsuccessful visits.
These findings do not establish that any single adaptation caused participation to remain stable, but they highlight the value of flexible delivery arrangements that preserve relationships with families and respond to practical constraints. They also show that families facing the most severe forms of instability remain difficult to reach, raising important equity issues.
Beyond ECAIL, the study shows that evaluating public health interventions is not only about understanding whether they work, but also how they are implemented, whom they reach, and how they adapt to changing contexts. These dimensions are essential for developing interventions accessible to families experiencing social disadvantage and helping reduce social inequalities
By Sandrine Lioret (Research Director, Inserm)
