Systematic Evaluation of How Indicators of Inequity and Disadvantage Are Measured and Reported in Population Health Evidence Syntheses

We present a systematic evaluation of population health reviews from the Cochrane Database (January 2013–February 2023) to evaluate how indicators of inequity or disadvantage are considered and reported in population health evidence syntheses. Descriptive analyses explored a representation of reviews across health-determinant categories (primary and secondary categories), summarised equity-focused reviews, and examined proportions and types of reviews that planned/completed a subgroup analysis using ≥1 indicators from the PROGRESS-Plus framework. Of 363 reviews included, a minority focused on interventions targeting wider determinants of health (n = 83, 22.9% as primary category), with a predominance related to individual lifestyle factors (n = 155, 42.7%) or health care services intervention (n = 97, 26.7%). An explicit equity focus was evident in 21 (5.8%) reviews that used PROGRESS/PROGRESS-Plus, and 28 (7.7%) targeting vulnerable groups. Almost half (n = 165, 45.6%) planned a subgroup analysis by ≥1 PROGRESS-Plus indicator, which was completed in 63 reviews (38.2% of 165). The non-completion of planned subgroup analyses was attributed to insufficient data (too few primary studies, data not reported by subgroups). Among the 165 reviews planning a subgroup analysis, age was the most cited indicator (n = 91, 55.2%), followed by gender/sex (n = 67, 40.6%), place (n = 47, 28.5%) and socio-economic status (n = 37, 22.4%). This study highlighted missed opportunities for learning about the impacts of health equity in population health evidence syntheses due to insufficient data. We recommend routine use of PROGRESS-Plus and greater consistency in socio-economic proxies (occupation, education, income, disadvantage measures) to facilitate meta-analyses and subgroup analyses.