Chapter 10. How to Assess the Evidence Concerning the Safety of Medical Interventions

  1. Hywel Williams MSC, PhD, FRCP Professor Dermato-Epidemiology Co-ordinating Editor
  1. Luigi Naldi MD Director

Published Online: 14 JAN 2009

DOI: 10.1002/9781444300161.ch10

Evidence-Based Dermatology, Second Edition

Evidence-Based Dermatology, Second Edition

How to Cite

Naldi, L. (2008) How to Assess the Evidence Concerning the Safety of Medical Interventions, in Evidence-Based Dermatology, Second Edition (ed H. Williams), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444300161.ch10

Editor Information

  1. Centre of Evidence-Based Dermatology, Nottingham University Hospital NHS Trust, Queen's Medical Centre, Nottingham, UK

Author Information

  1. Centro Studi GISED, Department of Dermatology, Ospedali Riuniti, Bergamo, Italy

Publication History

  1. Published Online: 14 JAN 2009
  2. Published Print: 11 APR 2008

ISBN Information

Print ISBN: 9781405145183

Online ISBN: 9781444300161



  • assessing evidence concerning medical intervention safety;
  • Prescription event monitoring (PEM);
  • measures of association;
  • “number needed to harm” (NNH) or NNTH;
  • exposure association with given event - relative risk or odds ratio;
  • signal assessment criteria in spontaneous surveillance systems


This chapter contains sections titled:

  • Introduction

  • Data sources

  • Back to the individual patient

  • References