Abstract
The altered landscape surrounding commissioning of public health provision has affected the nature and range of health visitor services across England. This is the first of two papers reporting evidence from a programme of research that focused on how health visiting works, also reporting service user and workforce perspectives. Evidence for a service model is offered, based on universal principles and maximising the capacity of the health visiting resource. Where service specifications fail to give careful attention to this evidence, the reshaped services for children and families may miss core ingredients that enable health visitors to make a difference, delivering a proportionate and successful child health programme for the early years.