Our scoping review is now published! A big thanks to Romana, Alisha and Anya for all their hard work on this one.
We explored how supermarket loyalty card data is being used in health research. We reviewed 44 studies that used loyalty card data to investigate a wide range of health-related outcomes—from diet and nutrition to public health interventions and medication use.
What we did:
- We searched four electronic databases (MEDLINE, EMBASE, PsycINFO, and Scopus)
- We systematically screened studies, extracting data on population characteristics, loyalty card and product details, health outcomes, advantages and limitations.
- Findings were synthesised using a narrative approach.
What we found:
- Studies focused on a range of products, including fish, dairy, alcohol and fruit and vegetables.
- Loyalty card data offers longitudinal, large-scale, objective insights at the individual, household and population level.
- Common challenges include missing data, difficulty linking purchases to nutritional composition and demographic biases.
- Exciting future directions include linking loyalty data with health records, evaluating policy campaigns and dietary interventions, and advancing computational analyses.
Our review highlights the value of loyalty card data in better understanding health.