Promises and pitfalls of meta-analysis in vaccine research

Meta-analysis continues to grow in usage despite increased concern regardin g its soundness. Over twenty meta-analyses directly pertain to vaccines. Va ccine researchers need to understand the technique as well as the criticism s, Meta-analysis involves four steps. First, the meta-analyst should establ ish certain criteria in advance of the second step where the meta-analyst g athers the data-the results of the individual studies. Third, the meta-anal yst assesses the individual studies for combinability and, fourth, the meta -analyst actually combines the data to generate conclusions. Vaccine meta-a nalyses have addressed a variety of vaccines and a variety of study objecti ves including efficacy, immunogenicity and safety, Three classical concerns revolve around the issue of publication bias, data dredging and individual study variability. Additionally, vaccine meta-analyses suffer concerns par ticular to the field of vaccine research. (C) 1999 Elsevier Science Ltd, Al l rights reserved.