**Background:** Health visiting is a long-established, nationally implemented programme in England that delivers the Healthy Child Programme (HCP) for children aged 0–5 years. It provides universal, preventive services including health screening, immunisation, health and development reviews, and parenting support, designed to be 'universal in reach—personalised in response'. There are five universal mandated contacts: at 28 weeks pregnancy, 10–14 days after birth, 6–8 weeks, 9–12 months, and 2–2.5 years. Families with higher needs may receive additional contacts or referrals. Despite its widespread delivery, there is a lack of evidence on the impact of 'usual service' health visiting contacts on child outcomes in England, and scant evidence on costs and benefits. Coverage is lower for ethnic minorities and children in deprived areas, yet those same groups may receive more additional contacts, highlighting the need for careful analysis. The COVID-19 pandemic has further strained services through staff redeployment. This study aims to provide robust evidence on the effectiveness, costs, and benefits of different levels and types of health visiting for different families in different local contexts.
**Methods:** This mixed-methods study with a sequential explanatory design integrates quantitative analysis of national linked administrative data with qualitative case studies and extensive stakeholder input. The quantitative component uses individual-level health visiting activity data from the Community Services Dataset (CSDS) linked with longitudinal data from hospital admissions, outpatient attendances, A&E, mortality (Hospital Episode Statistics), education (National Pupil Database), and children's social care (Child in Need and Looked after Children) via the Education and Child Health Insights from Linked Data (ECHILD) dataset. The study will analyse data for financial years 2018/2019 and 2019/2020, focusing on attended face-to-face contacts. A taxonomy of 3–5 commonly used models of health visiting across all local authorities in England is being developed (e.g., model 1: low universal coverage but highly targeted, mostly by qualified health visitors; model 2: high universal coverage but few additional contacts, mostly by band 5 nurses). Aggregate area-level outcomes (e.g., breastfeeding, vaccination coverage) will be sourced from Office for Health Improvement and Disparities Fingertips and The Children's Commissioner's Vulnerability Profiles.
To address confounding by indication (families with higher need receiving more contacts), the individual-level analysis will use propensity score matching to match children with similar underlying need (based on child characteristics at birth including gestational age, birth weight, ethnicity, area-level deprivation, number of siblings; and maternal characteristics before birth including age at first birth, history of mental health-related hospital admissions, GCSE-level qualifications, mother's contact with social care services in childhood) but different numbers of health visiting contacts. Multilevel regression models (logistic, Poisson, or linear) will evaluate relationships in the propensity-matched cohort, accounting for clustering within local authorities. The primary analysis will be restricted to the earliest birth for each woman from 2018/2019 onwards. Stratification by potential moderators (e.g., birth order, ethnicity, area-level deprivation) is planned. The area-level analysis will use linear mixed-effects models to analyse the relationship between health visiting model (from the taxonomy) and outcomes for years 2018/2019–2021/2022, adjusting for area-level characteristics.
Outcomes span all six HCP high-impact areas: (1) transition to parenthood and maternal/family mental health (unplanned hospital admissions for mental health, substance misuse or violence; maternal death by suicide; 6–8 weeks postpartum GP check); (2) breastfeeding (6–8 weeks); (3) healthy weight and nutrition (prevalence of overweight/obesity at reception; decayed, missing or filled teeth at age 5); (4) health literacy, accidents and minor illnesses (infant/child mortality; unplanned admissions for injury/ingestion; unplanned admissions for chronic conditions and gastroenteritis/LRTI; A&E attendance; vaccination coverage for MMR and DTaP/IPV/Hib/HepB); (5) ready to learn and narrowing the word gap ('good' level of development at 2.5-year review and at end of reception).
The economic analysis will adhere to NICE methods for public health interventions, comparing total costs to total benefits of different health visiting service delivery models. Costs will be estimated using CSDS-ECHILD data on contacts (including duration) combined with unit costs from an existing study, case study sites, or NHS reference costs. Benefits will be valued in monetary terms for outcomes with known long-term financial implications (e.g., A&E attendance, obesity). A secondary analysis will incorporate family and maternal health outcomes. Longer-term benefits (e.g., obesity, oral health, school exclusions, contact with social care) will be projected using study results and literature.
Qualitative case studies will be conducted in up to four local authorities selected to explain emerging findings while seeking maximum variation on geography, demographic profile, and local government. Data collection includes documentary analysis, in-depth interviews with health visiting practitioners, managers and commissioners, and focus groups or interviews with parents. Topic guides will explore how health visitors identify families at differing levels of need, how decisions on contact number/type/timing are made, and parents' experiences and perceptions.
Integration uses an 'advanced multistage mixed-methods framework' combining exploratory sequential (scoping qualitative data generating hypotheses), explanatory sequential (case study interviews explaining quantitative findings), and convergent (overlapping area-level impact and case studies) approaches. A 'constant comparative approach' will be used at analysis and interpretation stages, with regular integration meetings.
**Key Results:** This is a study protocol; no results are reported.
**Clinical Implications:** The findings are intended to inform national guidance on the health visiting component of the HCP, contributing to its modernisation by the Department of Health and Social Care and the Office for Health Improvement and Disparities. Evidence on impact, costs, and benefits will inform local leaders developing their Start for Life offer and local HCP, and submissions to the 2024 Spending Review. Policy briefings, lay summaries, peer-reviewed journal articles, and conference presentations are planned for dissemination to policymakers, practitioners, health visitors, and parents.