Skip to main content


Fig. 1 | BMC Medicine

Fig. 1

From: How effective are common medications: a perspective based on meta-analyses of major drugs

Fig. 1

Summary of effect sizes for common pharmacological treatments. The figure presents primary pharmacological intervention for a given therapy type, the primary outcome, descriptive statistics and efficacy measures. Effect sizes are expressed as standardized mean difference with corresponding confidence intervals on the right side and the AMSTAR score below. The graph in the middle shows a ranking of effect sizes according to Cohen: small effect size is no bigger than 0.2; medium effect size is around 0.5; and large effect sizes are bigger than 0.8. Marked with red color are outcomes that can be objectively measured and are patient-oriented [812, 1518, 2332]. The following drugs listed by the IMS Institute report were not included in the figure: thyroid preparations (no meta-analysis was found); anti-epileptics (no meta-analysis on monotherapy was found because current antiepileptic trials are add-on); hormonal contraceptives for birth control (no “disease” as an indication); and alpha-adrenergic antagonists for benign prostate hyperplasia (no SMD was provided or calculable). All values are statistically significant (except mortality for metformin). All additional confidence intervals can be obtained from the authors upon request. AMSTAR, a measurement scale for the assessment of the methodological quality of systematic reviews; ARD, absolute risk or response difference; CI, confidence interval; D, percentage of patients with the outcome in the drug group; MD, mean difference in original units; n, number of participants; N, number of trials; PL, percentage of patients with the outcome in the placebo group; PRR, percentage response ratio; SMD, standardized mean difference

Back to article page