Introduction: Recently, there has been a renewed interest in population descriptors; in particular, Race, Ethnicity, and Ancestry (REA). However, REA concepts remain poorly defined and inconsistently applied, which can diminish complex identities and increase healthcare inequalities.

Our aim is to explore how rising migrant populations and healthcare professionals interact with REA terms to develop a toolkit for data collection best practise.

Methods: Study 1 and study 2 are parallel exploratory qualitative studies with rising migrant populations residing in Leicester and healthcare professionals who use REA data in their job role respectively. Study 3 will be to triangulate the data using a mixed-method approach to create a toolkit to be used in healthcare, health research and health policy. Audio-recordings will be transcribed verbatim and analysed using reflexive thematic analysis methods.

Preliminary Results: These observations are derived from early discussions. Participants reported limited knowledge of ancestry, attributed to historical legacies such as border changes and migration. Other participants found existing ethnicity categories confusing or inadequate e.g. ‘African’ is vague, as the country has so many cultures within. Participants had a broad recognition of the value of collecting ethnicity and ancestry data in healthcare, particularly in relation to genetic conditions. PO005 “My doctor thought I had thalassemia, so they wanted to know my ancestry. It's more common in Middle Eastern people. I had to say my great grandparents are from Lithuania and Germany, when I’m Polish”