Reaching Priority Populations When Scaling Up: A Qualitative Study of Practitioners' Experiences of Implementing Early Childhood Health Interventions in Victoria, Australia

Implementing evidence-based health promotion programmes at scale is important for achieving population-level health outcomes. However, achieving equitable reach can be challenging. An evidence-based early-life nutrition and movement intervention (INFANT) is currently being implemented at scale in Australia. This study explored practitioners' perceptions about reaching priority population groups through INFANT or similar universal preventive health programmes and services implemented at scale. Fifteen semi-structured online interviews were conducted with purposively selected experienced practitioners. Interviews were transcribed and analysed using reflexive thematic analysis. Two main themes were developed, representing the complexities of reaching priority population groups through universal health programmes and services in early childhood. Theme 1: "We're not hitting the mark"-Underlying issues influence universal healthcare access, highlighted (a) the perception that parents felt out of place through a sense of not belonging or being unfamiliar with universal services and (b) that practical constraints and pressing priorities impacted access. Theme 2: "There are no easy answers"-Varied approaches can enhance engagement, but the path is not straightforward, encompassed (a) the importance of trust and familiarity with providers, (b) the suitability of programmes and services for target communities, and (c) factors such as practitioner uncertainty regarding approaches that could address the needs of families from priority populations and resourcing that can limit targeted efforts. Our findings highlight the complexities of achieving equitable reach during scale-up and the varied decision-making and resourcing for addressing inequity in a local context. While our findings identify local-level strategies to address equitable reach during scale-up, we emphasise that striving to achieve health equity should be embedded and prioritised in scale-up efforts.