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General medicine
Conducting one-stage IPD meta-analysis: which approach should I choose?
  1. Thomas R Fanshawe,
  2. Rafael Perera
  1. Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
  1. Correspondence to Dr Rafael Perera, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford OX1 2JD, UK; rafael.perera{at}

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Alternative methods for dealing with within trial clustering have been proposed for conducting individual participant data (IPD) ‘one-stage’ meta-analysis. Does it matter which one is used? Will it affect the estimates and their precision? 

Tom Fanshawe and Rafael Perera

Meta-analysis of studies using IPD is increasingly common and is likely to grow in popularity as a result of increased data sharing with repositories for collaborative data sharing become more established. IPD meta-analysis allows systematic reviews to pool data, beyond what is possible based only on the summary statistics, for example, intervention effects, reported in published papers and also provides the opportunity of fitting appropriate statistical methods to obtain summary estimates.

Two-stage and one-stage meta-analyses are the commonly used statistical approaches in IPD. In the ‘two-stage’ meta-analysis, the …

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  • Contributors TRF and RP selected the article to comment on. Both authors decided on the overall layout, wrote the comment and adjusted after suggestions from internal editors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; internally peer reviewed.

  • Patient consent for publication Not required.