Family Practice, Vol 15, 319-322, Copyright © 1998 by World Organization of Family Doctors
AG Edwards, IT Russell and NC Stott
Clinical practice frequently generates questions that are not easily
answered by randomized trials. On conventional hierarchies of evidence,
'weaker' study designs are often more feasible. Also, much research is not
well designed. Yet we still need to make best use of the available
evidence. Systematic reviews must therefore address the danger of
underestimating the evidence from relevant literature if it includes only
that of a certain methodological quality. This would run the risk of
missing or distorting the true message that the review is trying to
identify. We propose a classification of research which does not reject
studies on the basis of design alone, but recognizes the importance of
assessing the message or 'signal' within each piece of research. It
explicitly introduces judgement into the appraisal and synthesis of
evidence, and affords more flexibility in attaching weight to evidence that
might otherwise be lost. It includes an assessment of methodological
quality, balancing this against the weight of its message, rather than
rejecting studies which are below a certain threshold for quality.
Fundamentally flawed research will still be rejected, but more commonly
papers can still be used, tempering the importance that we attach to their
signal by the amount of 'noise' around that signal. The balance of these
two elements may be termed the 'signal to noise ratio'.
ORIGINAL CLINICAL RESEARCH
Signal versus noise in the evidence base for medicine: an alternative to hierarchies of evidence?
Department of General Practice, University of Wales College of Medicine, Llanedeyrn Health Centre, Cardiff, UK.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  N. Hughes, S. J. Closs, and D. Clark Experiencing Cancer in Old Age: A Qualitative Systematic Review Qual Health Res, August 1, 2009; 19(8): 1139 - 1153. [Abstract] [PDF]
|
|
|
|
 |
|
 S. A. Olivo, L. G. Macedo, I. C. Gadotti, J. Fuentes, T. Stanton, and D. J Magee Scales to Assess the Quality of Randomized Controlled Trials: A Systematic Review Physical Therapy, February 1, 2008; 88(2): 156 - 175. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Brereton, C. Carroll, and S. Barnston Interventions for adult family carers of people who have had a stroke: a systematic review Clinical Rehabilitation, October 1, 2007; 21(10): 867 - 884. [Abstract] [PDF]
|
|
|
|
 |
|
 A. Edwards, K. Hood, E. Matthews, D. Russell, I. Russell, J. Barker, M. Bloor, P. Burnard, J. Covey, R. Pill, et al. The Effectiveness of One-to-one Risk-communication Interventions in Health Care: A Systematic Review Med Decis Making, July 1, 2000; 20(3): 290 - 297. [Abstract] [PDF]
|
|
|
|
 |
|
 S. Fordham and C. Dowrick Is care of the dying improving? The contribution of specialist and non-specialist to palliative care Fam. Pract., December 1, 1999; 16(6): 573 - 579. [Abstract] [Full Text] [PDF]
|
|