title: Individual patient data meta-analysis of randomized anti-epileptic drug monotherapy trials.
abstract: Meta-analysis may be based on either aggregate data or individual patient data (IPD). Three reasons why IPD are desirable for the meta-analysis of anti-epileptic drug (AED) monotherapy trials are: (1) to undertake a more complete analysis of time-to-event outcomes; (2) to investigate the interaction between AED and type of epilepsy; and (3) to undertake re-analysis of the trial to obtain results for all relevant outcomes. We demonstrate that IPD meta-analysis is possible in AED research. Problems arose from missing data at four levels: (1) unknown trials; (2) known trials but no IPD supplied; (3) known trials but missing outcome data for some individuals within trials; and (4) known trials but missing covariate data for some individuals within trials. Empirical evidence of the reliability of meta-analyses based on aggregate rather than individual patient data is still lacking. Examples of other benefits such projects may bring include improvements to the design of a new trial in the area, in terms of the sample size considerations, the definition of outcomes and data collection.
authors.affiliation: Department of Mathematical Sciences, University of Liverpool, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: Williamson
authors.forename: A G
authors.initials: AG
authors.lastname: Marson
authors.forename: C
authors.initials: C
authors.lastname: Tudur
authors.forename: J L
authors.initials: JL
authors.lastname: Hutton
authors.forename: D
authors.initials: D
authors.lastname: Chadwick
mesh_terms: D000927:Anticonvulsants / Q000627:therapeutic use*; D004827:Epilepsy / Q000188:drug therapy; D006801:Humans; D015201:Meta-Analysis as Topic; D016032:Randomized Controlled Trials as Topic; D015203:Reproducibility of Results
chemical_list: D000927:Anticonvulsants