How Network Meta-Analyses Compare Adjunctive Antipsychotics in MDD

This episode, "How Network Meta-Analyses Compare Adjunctive Antipsychotics in MDD," has Dr. Citrome laying out the statistical groundwork behind every comparison that follows.

Before defining a network meta-analysis, Dr. Citrome walks through the statistical fundamentals that make one useful. He starts with the p-value, which only indicates whether a difference between a drug and placebo is statistically significant. It says nothing about the size of that treatment effect. Something can be statistically significant, he notes, while remaining clinically irrelevant. What actually matters is effect size: how large the difference between drug and placebo really is, and whether that difference is meaningful in day-to-day practice. Dr. Citrome points out that published trials tend to emphasize p-values over effect size, which becomes a problem once multiple studies need to be compared. If every individual trial simply shows statistical significance against placebo, that fact alone is not very informative for distinguishing between options. A meta-analysis addresses this by pooling trials together and examining the effect size differences between drug and placebo across the whole set. A network meta-analysis extends that idea further, taking a network of different trials and mapping the interrelationships among them. Some drugs are compared only against placebo; others may have been compared directly against each other, and both types of comparison get incorporated statistically. The output of a network meta-analysis is effect size, arranged both graphically and in numerical tables. This lets clinicians see which agent shows the largest effect, and whether these differences are real once variability is accounted for. Dr. Citrome flags that each effect size carries its own statistical uncertainty rather than being a fixed number, setting up the discussion of confidence intervals that follows in the next episode.

Our next episode, "First Network Meta-Analysis Compares Efficacy and Safety of MDD Adjunctive Therapies," puts that framework to work on a meta-analysis Dr. Citrome co-authored himself.