ArticleInternational journal of epidemiology2024
Overadjustment bias in systematic reviews and meta-analyses of socio-economic inequalities in health: a meta-research scoping review.
Article in International journal of epidemiology, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
15 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- The association between socioeconomic position and depression or suicidal ideation in low- and middle-income countries in Southeast Asia: a systematic review and meta-analysis.BMC public health · 2024Pooled it
- Associations of family socioeconomic indicators and physical activity of primary school-aged children: a systematic review.BMC public health · 2024Pooled it
- Not always towards the null: reconsidering the direction of overadjustment bias.International journal of epidemiology · 2026Article
- Do MASLD subtypes truly diverge in pregnancy risk, or do they reflect the same metabolic burden?Hepatology international · 2026Article
- Pain and the aging brain: beyond association toward action.Aging clinical and experimental research · 2026Article
- Long-term exposure to traffic noise and the incidence of hypertension: a systematic review and meta-analysis of prospective cohort studies.Frontiers in cardiovascular medicine · 2026Review
- Data-driven dietary patterns in relation to psychological distress and psychological quality of life among community-dwelling older adults in Shanghai, China: a cross-sectional study.Frontiers in nutrition · 2026Article
- On Mechanistic Interpretation of Cross-Sectional Mediation in Sitting Time and Urinary Leakage [Letter].International journal of women's health · 2026Article
- Development of the Kunonga framework for operationalising approaches to health inequality and/or inequity evidence syntheses.BMC public health · 2025Article
- Mediating impact of sleep quality and duration on the relationship between socio-economic conditions and pain.International journal of epidemiology · 2025Article
- Socioeconomic Disadvantage, All-Cause and Cause-Specific Mortality in Patients Treated With Maintenance Dialysis: A Mediation Analysis of Geographical Inequity and Multimorbidity.Kidney medicine · 2025Article
- Socioeconomic position across the life course and falls among middle- and older-aged adults: protocol for a systematic review.BMJ open · 2025Article
- Intergenerational educational mobility and mental health: Evidence from a Filipino birth cohort.PLOS global public health · 2025Article
- Consideration of overadjustment bias in guidelines and tools for systematic reviews and meta-analyses of observational studies is long overdue.International journal of epidemiology · 2024Article
- Social health gradient and risk factors among patients hospitalized for COVID-19 and pre-pandemic respiratory infections. A linked national individual case-control study in Belgium.Frontiers in public health · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
backgroundOveradjustment bias occurs when researchers adjust for an explanatory variable on the causal pathway from exposure to outcome, which leads to biased estimates of the causal effect of the exposure. This meta-research review aimed to examine how previous systematic reviews and meta-analyses of socio-economic inequalities in health have managed overadjustment bias.
methodsWe searched Medline and Embase until 16 April 2021 for systematic reviews and meta-analyses of observational studies on associations between individual-level socio-economic position and health outcomes in any population. A set of criteria were developed to examine methodological approaches to overadjustment bias adopted by included reviews (rated Yes/No/Somewhat/Unclear).
resultsEighty-four reviews were eligible (47 systematic reviews, 37 meta-analyses). Regarding approaches to overadjustment, whereas 73% of the 84 reviews were rated as Yes for clearly defining exposures and outcomes, all other approaches were rated as Yes for <55% of reviews; for instance, 5% clearly defined confounders and mediators, 2% constructed causal diagrams and 35% reported adjusted variables for included studies. Whereas only 2% included overadjustment in risk of bias assessment, 54% included confounding. Of the 37 meta-analyses, 16% conducted sensitivity analyses related to overadjustment.
conclusionsOur findings suggest that overadjustment bias has received insufficient consideration in systematic reviews and meta-analyses of socio-economic inequalities in health. This is a critical issue given that overadjustment bias is likely to result in biased estimates of health inequalities and accurate estimates are needed to inform public health interventions. There is a need to highlight overadjustment bias in review guidelines.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.