Process evaluation of a breastfeeding support intervention to promote exclusive breastfeeding and reduce social inequity: a mixed-methods study in a cluster-randomised trial.

Background: Breastfeeding is a powerful public health intervention that produces long-term health benefits. However, in high-income countries such as Denmark, breastfeeding rates are suboptimal and unequally distributed across socio-economic positions. The 'Breastfeeding - a good start together' intervention, to promote longer duration of exclusive breastfeeding and reduce social inequity, was implemented in a cluster-randomised trial during 2022-2023 across 21 municipalities in two Danish regions. A process evaluation was conducted to assess the implementation, mechanisms of impact, and possible contextual factors affecting the intervention.

Methods: The study was guided by the Medical Research Council's guidance for conducting process evaluations and employed a mixed-methods approach in a convergence design. Quantitative data: contextual mapping survey (n = 20), health visitor survey (n = 284), health visitor records from 20 clusters and intervention website statistics. Qualitative data: dialogue meetings (n = 7), focus groups (n = 3) and interviews (n = 8).

Results: Overall, the intervention was delivered as planned to intended recipients, with few exceptions. Health visitors responded positively to the intervention, noting that it fitted well within their usual practice and enhanced families' chances of breastfeeding. Mothers expressed having received the intervention with few exceptions, and reacted positively to the intervention. Although health visitors were concerned about the potential stigmatisation of mothers receiving the intensified intervention, none of the interviewed mothers felt stigmatised. Contextual factors impacting the intervention implementation and mechanisms included staff and management turnover, project infrastructure and mothers' context, such as resources, social networks and previous experiences. The overall fidelity of the intervention delivery was high.

Conclusions: Health visitors and families responded well to the intervention. Interventions aimed at enabling health care providers to deliver simplified and structured breastfeeding support, in alignment with support provided in other sectors of the health care system, may increase breastfeeding rates and reduce social inequity in breastfeeding, even in international contexts.

Trial registration: Clinical Trials: NCT05311631. First posted April 5, 2022.