A modified Delphi exercise to determine the extent of consensus with OMERACT outcome domains for studies of acute and chronic gout.

OBJECTIVES: To reach consensus with recommendations made by an OMERACT Special Interest Group (SIG).

METHODS: Rheumatologists and industry representatives interested in gout rated and clarified, in three iterations, the importance of domains proposed by the OMERACT SIG for use in acute and chronic gout intervention studies. Consensus was defined as a value of less than 1 of the UCLA/RAND disagreement index.

RESULTS: There were 33 respondents (61% response rate); all agreed the initial items were necessary, except "total body urate pool". Additional domains were suggested and clarification sought for defining "joint inflammation" and "musculoskeletal function". Items that demonstrated no clear decision were re-rated in the final iteration. There were six highly rated items (rating 1-2) with four slightly lower rating items (rating 3) for acute gout; and 11 highly rated items with eight slightly lower ratings for chronic gout.

CONCLUSIONS: Consensus is that the following domains be considered mandatory for acute gout studies: pain, joint swelling, joint tenderness, patient global, physician global, functional disability; and for chronic gout studies: serum urate, gout flares, tophus regression, health-related quality of life, functional disability, pain, patient global, physician global, work disability and joint inflammation. Several additional domains were considered discretionary.

[Erratum appears in Ann Rheum Dis. 2008 Nov;67(11):1652. Note: Mellado, J Vazquez [corrected to Vazquez-Mellado, J]]

Aim

The purpose of this study was to formally determine the extent of consensus with these recommendations using a Delphi approach.

Contributors

Taylor, W. J. Schumacher, H. R., Jr. Baraf, H. S. B. Chapman, P. Stamp, L. Doherty, M. McQueen, F. Dalbeth, N. Schlesinger, N. Furst, D. E. Vazquez-Mellado, J. Becker, M. A. Kavanaugh, A. Louthrenoo, W. Bardin, T. Khanna, D. Simon, L. S. Yamanaka, H. Choi, H. K. Zeng, X. Strand, V. Grainger, R. Clegg, D. Singh, J. A. Diaz-Torne, C. Boers, M. Gow, P. Barskova, V. G.

Publication

Journal: Annals of the Rheumatic Diseases
Volume: 67
Issue: 6
Pages: 888 - 91
Year: 2008
DOI: 10.1136/ard.2007.079970

Further Study Information

Current Stage: Not Applicable
Date:
Funding source(s): None stated


Health Area

Disease Category: Rheumatology

Disease Name: Gout

Target Population

Age Range: Unknown

Sex: Either

Nature of Intervention: Any

Stakeholders Involved

- Clinical experts
- Pharmaceutical industry representatives

Study Type

- COS for clinical trials or clinical research

Method(s)

- Delphi process

Fifty-four rheumatologists and industry representatives interested in gout were identified from the OMERACT Gout mailing list and a previous Delphi exercise that examined the question of gout flare. Respondents were asked to rate the importance of measuring domains in acute gout and chronic gout intervention studies on a seven point scale (1=definitely necessary to 7=definitely not necessary), using a web-based questionnaire. The domains suggested by the OMERACT SIG were used for the first iteration, supplemented by domains of ‘‘physician global assessment’’ and ‘‘work disability’’ for acute gout and ‘‘work disability’’, ‘‘physician global assessment’’, ‘‘joint inflammation’’, ‘‘pain’’ and ‘‘total body urate pool’’ for chronic gout studies. These extra domains were selected on the basis of literature review and expert opinion. Additional domains felt to be of importance were also solicited from Delphi respondents.

Consensus was defined by the UCLA/RAND disagreement index, whereby values of less than 1 indicated agreement. This index is essentially calculated from the 30th and 70th percentile of the respondents’ ratings, adjusted for symmetry between the central point of the interpercentile range and the mid-point of the rating scale. New items, re-worded items, and items for which there was disagreement and/or median rating of 4 (neither agreement nor disagreement) were re-rated in the second iteration. In the final (third) iteration, no new items were introduced and only items for which there was disagreement and/or median rating of 4 were re-rated.