Background
Cost-of-living crises are damaging to population mental health and require a public health response. It is important to assess whether public health interventions are effective. We aimed to identify population-level methods and measures and the appropriateness of the measures for vulnerable populations.

Methods
A rapid evidence review was undertaken. Nineteen databases, including grey literature, were searched for evidence published between 1970 and April 2023.

Results
Seven reviews, nine primary studies and two reports from grey literature were identified. Methods consisted of analyses of existing data from national or regional cohort studies, household panel surveys, repeated cross-sectional surveys, routine medical data, or data on suicide death rates. Twelve brief validated mental health measurement tools, embedded in population-level surveys, were identified. Two quasi-experimental studies used data from a UK household panel survey to examine the impact of the introduction of specific welfare policies on mental health. Studies identified socio-economic vulnerabilities, but it was not possible to determine whether data were effectively captured from people from minority ethnic groups.

Conclusion
Population-level surveys can be used in quasi-experimental studies to measure the effects of a public health initiative with specific roll out dates to tackle cost-of-living impacts. It is unclear as to whether the identified methods and tools are suitable for use with people from minority ethnic groups.