ReviewBiometrical journal. Biometrische Zeitschrift2018
When should meta-analysis avoid making hidden normality assumptions?
Review in Biometrical journal. Biometrische Zeitschrift, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 67 papers, 19 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
67 citing papers in PubMed, 19 syntheses or guidelines pooled it.
- Meta-analysis models relaxing the random-effects normality assumption: methodological systematic review and simulation study.BMC medical research methodology · 2025Pooled it
- A meta-analysis on the potency of foot-and-mouth disease vaccines in different animal models.Scientific reports · 2024Pooled it
- A meta-analysis for prevalence of infectious laryngotracheitis in chickens in mainland China in 1981-2022.BMC veterinary research · 2024Pooled it
- Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious teeth: A systematic review and meta-analysis.Clinical and experimental dental research · 2023Pooled it
- Two-stage or not two-stage? That is the question for IPD meta-analysis projects.Research synthesis methods · 2023Pooled it
- The prevalence of vancomycin-resistant Staphylococcus aureus in Ethiopia: a systematic review and meta-analysis.Antimicrobial resistance and infection control · 2023Pooled it
- Metal Exposure and Risk of Parkinson Disease: A Systematic Review and Meta-Analysis.American journal of epidemiology · 2023Pooled it
- The normality assumption on between-study random effects was questionable in a considerable number of Cochrane meta-analyses.BMC medicine · 2023Pooled it
- A Bayesian model for combining standardized mean differences and odds ratios in the same meta-analysis.Journal of biopharmaceutical statistics · 2023Pooled it
- Heterogeneity estimation in meta-analysis of standardized mean differences when the distribution of random effects departs from normal: A Monte Carlo simulation study.BMC medical research methodology · 2023Pooled it
- A meta-analysis: the efficacy and effectiveness of polypeptide vaccines protect pigs from foot and mouth disease.Scientific reports · 2022Pooled it
- Jointly pooling aggregated effect sizes and their standard errors from studies with continuous clinical outcomes.Biometrical journal. Biometrische Zeitschrift · 2022Pooled it
- Estimation of the COVID-19 mean incubation time: Systematic review, meta-analysis, and sensitivity analysis.Journal of medical virology · 2022Pooled it
- Meta-analysis of the severe acute respiratory syndrome coronavirus 2 serial intervals and the impact of parameter uncertainty on the coronavirus disease 2019 reproduction number.Statistical methods in medical research · 2022Pooled it
- Estimating the reference interval from a fixed effects meta-analysis.Research synthesis methods · 2021Pooled it
- A metaresearch study revealed susceptibility of Covid-19 treatment research to white hat bias: first, do no harm.Journal of clinical epidemiology · 2021Pooled it
- Study specific prediction intervals for random-effects meta-analysis: A tutorial: Prediction intervals in meta-analysis.Research synthesis methods · 2021Pooled it
- Evaluation of various estimators for standardized mean difference in meta-analysis.Statistics in medicine · 2021Pooled it
- Meta-analysis of published excess relative risk estimates.Radiation and environmental biophysics · 2020Pooled it
- Practical Guidance on Fisher's z Transformation for Meta-Analysis of Pearson's Correlation Coefficients.Journal of evidence-based medicine · 2026Article
7 more citing papers are in PubMed but not listed here.
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Authors and funding
2 authors.
Funding
Abstract
Meta-analysis is a widely used statistical technique. The simplicity of the calculations required when performing conventional meta-analyses belies the parametric nature of the assumptions that justify them. In particular, the normal distribution is extensively, and often implicitly, assumed. Here, we review how the normal distribution is used in meta-analysis. We discuss when the normal distribution is likely to be adequate and also when it should be avoided. We discuss alternative and more advanced methods that make less use of the normal distribution. We conclude that statistical methods that make fewer normality assumptions should be considered more often in practice. In general, statisticians and applied analysts should understand the assumptions made by their statistical analyses. They should also be able to defend these assumptions. Our hope is that this article will foster a greater appreciation of the extent to which assumptions involving the normal distribution are made in statistical methods for meta-analysis. We also hope that this article will stimulate further discussion and methodological work.
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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.