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.