Journal of Epidemiology & Community Health, February 1999;Vol 53:p 105-111
Deborah Charnock, Sasha Shepperd, Gill Needham, Robert Gann
To develop a short instrument, called DISCERN, which will enable patients and information providers to judge the quality of written information about treatment choices. DISCERN will also facilitate the production of new, high quality, evidence-based consumer health information.
An expert panel, representing a range of expertise in consumer health information, generated criteria from a random sample of information for 3 medical conditions with varying degrees of evidence: myocardial infarction, endometriosis and chronic fatigue syndrome. A draft instrument, based on this analysis, was tested by the panel on a random sample of new material for the same 3 conditions. The panel re-drafted the instrument to take account of the results of the test. The DISCERN instrument was finally tested by a national sample of 15 information providers and 13 self-help group members on a random sample of leaflets from 19 major national self-help organisations. Participants also completed an 8-item questionnaire concerning the face and content validity of the instrument.
Chance corrected agreement (weighted kappa) for the overall quality rating was k=0.53 (95% CI k=0.48 to k=0.59) amongst the expert panel, k=0.40 (95% CI k=0.36 to k=0.43) amongst information providers and k=0.23 (95% CI k=0.19 to k=0.27) amongst self-help group members. Higher agreement levels were associated with experience of using the instrument and with professional knowledge of consumer health information. Levels of agreement varied across individual items on the instrument, reflecting the need for subjectivity in rating certain criteria. The trends in levels of agreement were similar amongst all groups. The final instrument consisted of 15 questions plus an overall quality rating. Responses to the questionnaire following the final testing revealed the instrument to have good face and content validity and to be generally applicable.
DISCERN is a reliable and valid instrument for judging the quality of written consumer health information. Whilst some subjectivity is required for rating certain criteria, the findings demonstrate that the instrument can be applied by experienced users and providers of health information to discriminate between publications of high and low quality. The instrument will also be of benefit to patients, though its use will be improved by training.
University of Oxford, Division of Public Health and Primary Health Care, Health
Services Research Unit, Institute of Health Sciences, Oxford
D Charnock, S Shepperd*
Buckinghamshire Health Authority, Aylesbury, Bucks
The Help for Health Trust, Winchester, Hampshire
Dr S Shepperd, Department of Primary Health Care and General Practice, Division of Primary Care and Population Health Sciences, Imperial College of Science, Technology and Medicine, St. Mary's Campus, Norfolk Place, London W2 1PG.