News - Interdisciplinary Centre for Ethics - Faculty of Philosophy

[Important! Event date changed] 26th October 2020: Research seminar online - Mariusz Maziarz (Jagiellonian University): Is meta-analysis a reliable source of evidence for decisions in the clinic?

We have the pleasure to invite you for a research seminar in the ‘BIOUNCERTAINTY’ research project. The subject of the seminar is 'Is meta-analysis a reliable source of evidence for decisions in the clinic?' and it will be delivered by Mariusz Maziarz (Jagiellonian University). The seminar will take place on Monday, 26th of October, at 5:30pm on MS Teams (link below).

Abstract: Literature-based meta-analysis is a standard technique applied to pooling results of individual studies used in medicine and social sciences. It has been criticized for [1] being too malleable to constrain results, [2] averaging incomparable values, [3] lacking a measure of strength of evidence, and [4] problems with systematic bias of individual studies. Despite these epistemic concerns, the current practice of decision-making and preparing clinical guidance relies to a high degree on evidence from meta-analysis. We argue against the use of literature-based meta-analysis of RCTs for assessment of treatment efficacy by showing that therapeutic decisions based on meta-analytic average of individual studies are not optimal given the full scope of existing evidence. The argument proceeds with discussing examples and analyzing properties of some common meta-analytic techniques. First, we demonstrate that the use of meta-analysis can lead to reporting statistically significant results despite limited efficacy of the treatment. This, in turn, leads to a huge number needed to treat (NNT) and an unfavorable tradeoff between benefits and harms of the treatment. Second, we show that meta-analytic confidence intervals (CI) are too narrow comparing to the variability of treatment outcomes reported by individual studies. Third, based on a review of studies comparing results of literature-based meta-analysis and IPD meta-analysis that report non-systematic differences in treatment effect estimates, we conclude that literature-based meta-analysis lacks reliability. Finally, we analyze amalgamating conflicting RCTs (i.e., studies reporting both positive and negative treatment effects). In this case, meta-analysis averages out the differences among studies and leads to a loss of information if no mediating variable can be found. Despite these problems, literature-based meta-analysis is useful for the assessment of harms. We support two alternative approaches to concluding systematic literature review: meta-analysis of individual patient data (IPD) and qualitative review employing mechanistic evidence.

Mariusz Maziarz studied econometrics and international economic relations at the Warsaw School of Economics. He is currently completing his doctorate at the Wrocław University of Economics and has started studies at the Doctoral School of Humanities at the Jagiellonian University. Mariusz is also an assistant researcher in the Interdisciplinary Centre for Ethics in the BIOUNCERTAINTY project.

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