Development of a provisional core domain set for polymyalgia rheumatica: Report from the Outcome Measures in Rheumatology (OMERACT) 12 polymyalgia rheumatica working group

Objective. The Outcome Measures in Rheumatology (OMERACT) polymyalgia rheumatica (PMR) working group aims to develop a core set of outcome measures to be used in clinical trials for PMR. Previous reports from OMERACT 11 included a qualitative study of the patient experience and a preliminary literature review. Methods. A 3-round Delphi survey of clinicians and patients with PMR was undertaken to identify a candidate core domain set for PMR research. Additionally, a literature review of outcome measures and their respective measurement instruments was undertaken. Meetings of patient research partners and clinicians were convened to review face validity of the provisional core domain set, which was subsequently presented and discussed at the OMERACT 12 congress. Results. Of the 60 clinicians taking part in round 1, 55 took part in round 2 and 51 in round 3. Of the 55 patients who took part in round 1, 46 and 35 took part in subsequent rounds. In total, 91% of participants in round 3 deemed the resulting draft core domain set reasonable. The literature review identified 28 studies for full review. Measurement instruments for each proposed domain were identified. Clinicians are highly aware of glucocorticoid-related adverse effects, but there is relatively little evidence about their true prevalence and severity, especially in PMR. Conclusion. A provisional core domain set, presented for clinical trials in PMR, comprises acute phase markers, physical function, death, glucocorticoid-related adverse events, and development of giant cell arteritis. Measurement instruments are suggested that may cover each domain, but these require formal validation for clinical trials in PMR.