Studies that show a significant effect of treatment are more likely to be published, be published
in English, be cited by other authors, and produce multiple publications than other studies…

Publication bias and related bias in meta‐analysis is often examined by visually checking
for asymmetry in funnel plots of treatment effect against its standard error. Formal statistical …

The findings of medical research are often met with considerable scepticism, even when they
have apparently come from studies with sound methodologies that have been subjected to …

Non-randomised studies of the effects of interventions are critical to many areas of healthcare
evaluation, but their results may be biased. It is therefore important to understand and …

Assessment of risk of bias is regarded as an essential component of a systematic review on
the effects of an intervention. The most commonly used tool for randomised trials is the …

In 2003, the QUADAS tool for systematic reviews of diagnostic accuracy studies was
developed. Experience, anecdotal reports, and feedback suggested areas for improvement; …

… Jonathan AC Sterne, professor of medical statistics and epidemiology1, … Jonathan
Sterne and colleagues describe the appropriate use and reporting of the multiple imputation …

Importance Effective therapies for patients with coronavirus disease 2019 (COVID-19) are
needed, and clinical trial data have demonstrated that low-dose dexamethasone reduced …

Funnel plots, and tests for funnel plot asymmetry, have been widely used to examine bias in
the results of meta-analyses. Funnel plot asymmetry should not be equated with publication …

Flaws in the design, conduct, analysis, and reporting of randomised trials can cause the
effect of an intervention to be underestimated or overestimated. The Cochrane Collaboration’s …