Evaluating novel agent effects in multiple‐treatments meta‐regression
- 4 August 2010
- journal article
- research article
- Published by Wiley in Statistics in Medicine
- Vol. 29 (23), 2369-2383
- https://doi.org/10.1002/sim.4001
Abstract
Multiple-treatments meta-analyses are increasingly used to evaluate the relative effectiveness of several competing regimens. In some fields which evolve with the continuous introduction of new agents over time, it is possible that in trials comparing older with newer regimens the effectiveness of the latter is exaggerated. Optimism bias, conflicts of interest and other forces may be responsible for this exaggeration, but its magnitude and impact, if any, needs to be formally assessed in each case. Whereas such novelty bias is not identifiable in a pair-wise meta-analysis, it is possible to explore it in a network of trials involving several treatments. To evaluate the hypothesis of novel agent effects and adjust for them, we developed a multiple-treatments meta-regression model fitted within a Bayesian framework. When there are several multiple-treatments meta-analyses for diverse conditions within the same field/specialty with similar agents involved, one may consider either different novel agent effects in each meta-analysis or may consider the effects to be exchangeable across the different conditions and outcomes. As an application, we evaluate the impact of modelling and adjusting for novel agent effects for chemotherapy and other non-hormonal systemic treatments for three malignancies. We present the results and the impact of different model assumptions to the relative ranking of the various regimens in each network. We established that multiple-treatments meta-regression is a good method for examining whether novel agent effects are present and estimation of their magnitude in the three worked examples suggests an exaggeration of the hazard ratio by 6 per cent (2–11 per cent). Copyright © 2010 John Wiley & Sons, Ltd.Keywords
This publication has 29 references indexed in Scilit:
- Comparative efficacy and acceptability of 12 new-generation antidepressants: a multiple-treatments meta-analysisThe Lancet, 2009
- Mixed treatment comparison with multiple outcomes reported inconsistently across trials: Evaluation of antivirals for treatment of influenza A and BStatistics in Medicine, 2008
- Network meta-analysis: simultaneous meta-analysis of common antiplatelet regimens after transient ischaemic attack or strokeEuropean Heart Journal, 2008
- Outcomes associated with drug-eluting and bare-metal stents: a collaborative network meta-analysisThe Lancet, 2007
- Incident diabetes in clinical trials of antihypertensive drugs: a network meta-analysisThe Lancet, 2007
- Using mixed treatment comparisons and meta-regression to perform indirect comparisons to estimate the efficacy of biologic treatments in rheumatoid arthritisStatistics in Medicine, 2006
- Mixed Comparison of Stroke Prevention Treatments in Individuals With Nonrheumatic Atrial FibrillationArchives of Internal Medicine, 2006
- Assessing Evidence Inconsistency in Mixed Treatment ComparisonsJournal of the American Statistical Association, 2006
- Combination of direct and indirect evidence in mixed treatment comparisonsStatistics in Medicine, 2004
- Bayesian Measures of Model Complexity and FitJournal of the Royal Statistical Society Series B: Statistical Methodology, 2002