3. What is Good Evidence for a Clinical Decision?

  1. Jeremy Howick1,2

Published Online: 23 MAR 2011

DOI: 10.1002/9781444342673.ch3

The Philosophy of Evidence-Based Medicine

The Philosophy of Evidence-Based Medicine

How to Cite

Howick, J. (2011) What is Good Evidence for a Clinical Decision?, in The Philosophy of Evidence-Based Medicine, Wiley-Blackwell, Oxford, UK. doi: 10.1002/9781444342673.ch3

Author Information

  1. 1

    Centre for Evidence-Based Medicine, Department of Public Health and Primary Care, University of Oxford, Oxford, UK

  2. 2

    Department of Science and Technology Studies, University College London, London, UK

Publication History

  1. Published Online: 23 MAR 2011
  2. Published Print: 8 APR 2011

ISBN Information

Print ISBN: 9781405196673

Online ISBN: 9781444342673



  • randomization, double masking, and placebo controls - ruling out confounding factors;
  • evaluation of EBM views - of what counts as “good” evidence;
  • decisions, whether to use an intervention - and non-evidential variables, patient values and cost;
  • evidence for clinical effectiveness - strong evidence that a treatment has “effects”;
  • useful in clinical practice - outcomes being patient-relevant;
  • patient relevant outcomes - those that make people live better or longer;
  • interventions, positive effects on patient-relevant outcomes - negative side-effects outweighing positive benefits;
  • Long-term Intervention with Pravastatin in Ischaemic Disease (LIPID) Study Group - Worrall's point, very act of taking medication being a harmful side-effect;
  • results of study, patients in routine practice - having “external validity”;
  • useful for clinical practice - treatment, the best available option


This chapter contains sections titled:

  • Introduction

  • Evidence for clinical effectiveness

  • Strong evidence tells us what?