Meta-analysis of Observational Studies

Meta-analyzing Rare Diseases
  • Ton J. Cleophas
  • Aeilko H. Zwinderman


Controlled long term open evaluation studies will be applied, if clinical trials are not feasible. Particularly, for the study of rare events, such studies have been published.

In the current chapter two open evaluation meta-analyses from our group will be reviewed. The first meta-analysis was homogeneous and robust. The scientific method was helpful to confirm its prior scientific question. The second meta-analysis was different. It only included studies either performed by internists or by pharmacists. The null-hypothesis was: no difference in outcome between one study and the other. In this meta-analysis heterogeneity was a benefit rather than pitfall, because the null-hypothesis was no heterogeneity, that, hopefully, could be rejected.


Adverse Drug Effect Traditional Risk Factor Pool Odds Ratio Coronary Collateral Multiple Confounder 
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  1. More background, theoretical and mathematical information of meta-analyses is given in Statistics applied to clinical studies 5th edition, Chaps. 32–34 and 48, Springer Heidelberg Germany, 2012, from the same authors.Google Scholar

Copyright information

© Springer International Publishing Switzerland 2017

Authors and Affiliations

  • Ton J. Cleophas
    • 1
  • Aeilko H. Zwinderman
    • 2
  1. 1.Department of MedicineAlbert Schweitzer HospitalSliedrechtThe Netherlands
  2. 2.Department of Epidemiology and BiostatisticsAcademic Medical CenterAmsterdamThe Netherlands

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