Document resource
There is a balance when determining the sample size of a new study: with too few participants, the study may not detect an effect; with too many, some participants may undergo inferior treatments unnecessarily. Both scenarios are wasteful and unethical. Furthermore, when evaluating healthcare, it is desirable to collate and synthesise evidence from multiple sources, 1 with meta-analysis being the standard statistical method for quantitatively summarising evidence from sufficiently homogenous studies.2