THE INTERRATER RELIABILITY OF A GENERIC MEASURE OF SEVERITY OF ILLNESS

Background. There has been increasing interest in the development of m easures to quantify baseline severity of illness and thus provide a mo re meaningful interpretation of health outcomes. Objective. We aimed t o assess the inter-rater reliability of a generic measure of illness s everity, the Duke University Severity of Illness (DUSOI) checklist. Me thods. Selected general practices and hospital outpatient departments across Tyneside and Humberside in the UK were used as the setting. Thi rty-three clinicians were posted copies of the same set of 14 patient records and asked to rate the severity of illness of each patient usin g the DUSOI. The subjects were 27 GPs, three consultant chest physicia ns and three diabetologists. The main outcome measures were: (i) intra class correlation coefficients used to express clinician agreement upo n severity scores; and (ii) a 'gold standard', constructed in order to assess clinician agreement upon the health problems identified in the patient record to be considered as constituents of overall severity. Results. It was found that the degree of inter-rater reliability of se verity scoring was satisfactory, with an intraclass correlation coeffi cient of 0.43. In terms of identification of problems to be rated, the re was considerable agreement between raters and a specially compiled 'gold standard' of health problems. Conclusion. The DUSOI has potentia l use in routine clinical practice, but strategies should be developed in order to maximize the reliability of rating illness severity on su ch a generic measure.