Abstract
The meta‐analysis of multi‐centre trials can be based on either fixed or random effect models. This paper argues for the general use of random effect models, and illustrates the value of non‐parametric maximum likelihood (NPML) analysis of such trials. The same general approach unifies administrative ‘league table’ analyses in epidemiological and other studies. Several examples of the NPML analysis are given, including a 70‐centre trial. Copyright © 1999 John Wiley & Sons, Ltd.