Unpacking tick-boxes: considerations and recommendations for collecting, analysing, and interpreting ethnicity data.

Ethnicity is an important variable in health and social science research, but working quantitatively with ethnicity data is complex because the construct is multifaceted, fluid, subjective, and political in nature. This necessitates careful consideration within the context of, and issues related to, the collection and classification of ethnicity data. Researchers' methodological decisions regarding ethnicity data can impact substantive research outcomes and implications for policy and practice. This critical review provides an overview of the conceptualisation and sociohistorical context of ethnicity, followed by a thorough discussion of the methodological issues in the collection and analysis of ethnicity data with a focus on the Aotearoa New Zealand context. It then offers comprehensive guidance and recommendations for quantitative researchers. With an emphasis on researcher criticality, reflexivity, and the importance of upholding the data sovereignty of Indigenous and minoritised ethnic groups, this review equips data users with the information needed to conduct ethical, equitable, robust, and scientifically-informed research involving ethnicity.