Use of Intersectionality Theory in Interventional Health Research in High-Income Countries: A Scoping Review.

Background: Intersectionality theory posits that considering a single axis of inequality is limited and that considering (dis)advantage on multiple axes simultaneously is needed. The extent to which intersectionality has been used within interventional health research has not been systematically examined. This scoping review aimed to map out the use of intersectionality. It explores the use of intersectionality when designing and implementing public health interventions, or when analysing the impact of these interventions.

Methods: We undertook systematic searches of Medline and Scopus from inception through June 2021, with key search terms including "intersectionality", "interventions" and "public health". References were screened and those using intersectionality and primary data from high-income countries were included and relevant data synthesised.

Results: After screening 2108 studies, we included 12 studies. Six studies were qualitative and focused on alcohol and substance abuse (two studies), mental health (two studies), general health promotion (one study) and housing interventions (one study). The three quantitative studies examined mental health (two studies) and smoking cessation (one study), while the three mixed-method studies examined mental health (two studies) and sexual exploitation (one study). Intersectionality was used primarily to analyse intervention effects (eight studies), but also for intervention design (three studies), and one study used it for both design and analysis. Ethnicity and gender were the most commonly included axes of inequality (11 studies), followed by socio-economic position (10 studies). Four studies included consideration of LGBTQ+ and only one considered physical disability. Intersectional frameworks were used by studies to formulate specific questions and assess differences in outcomes by intersectional markers of identity. Analytical studies also recommended intersectionality approaches to improve future treatments and to structure interventions to focus on power and structural dynamics.

Conclusions: Intersectionality theory is not yet commonly used in interventional health research, in either design or analysis. Conditions such as mental health have more studies using intersectionality, while studies considering LGBTQ+ and physical disability as axes of inequality are particularly sparse. The lack of studies in our review suggests that theoretical and methodological advancements need to be made in order to increase engagement with intersectionality in interventional health.