The organisation’s purpose is to protect and improve the health and wellbeing of the nation through a wide range of functions. These include delivering national screening programmes, health protection and microbiology services; advising government on public health policy and legislation; developing evidence-based interventions and delivering health improvement programmes; driving data-informed population health and delivering healthcare improvement support. The organisation is also a World Health Organization (WHO) Collaborating Centre on investment for health and wellbeing. Prior to joining Public Health Wales, Tracey was the inaugural Chief Executive of the Health Information and Quality Authority (HIQA) in the Republic of Ireland, which is the health and social care regulator for the country. Prior to her more recent roles, her medical career was in emergency medicine, emergency care services and health system reform.