217 Results of a patient survey on feasibility and face validity of outcome measures for intended use in future studies enrolling participants with polymyalgia rheumatica

Background: Too few studies to date have used robust, validated outcome measures that are relevant to patients resulting in difficulty in comparing results from trials. The Outcome Measures in Rheumatology (OMERACT) polymyalgia rheumatica (PMR) working group have previously developed a core domain set for PMR and identified candidate outcome measures following the OMERACT Filter 2.1 Instrument Selection Algorithm. The aim of this study was to conduct a survey amongst patients with PMR to evaluate the face validity, acceptability and domain match of the proposed candidate outcome measures.

Methods: The previously identified core domains and measurement instruments comprised: 1. Pain severity: visual analogue scale (VAS), numerical rating score (NRS); 2. Stiffness: severity: VAS, NRS; duration of morning stiffness: minutes; 3. Physical Function: modified Health Assessment Questionnaire (mHAQ), Health Assessment Questionnaire Disability Index (HAQ-DI); 4. Inflammation: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR). A structured online, anonymous questionnaire following the OMERACT instrument selection algorithm was disseminated to patient support groups via their own networks and online forums. Free text answers were analysed using descriptive thematic analysis to explore respondent views of the candidate instruments in relation to participants’ lived experience of PMR.

Results: 78 people with PMR from six countries (UK, France, USA, Canada, Australia and New Zealand) participated in the survey. Disease duration ranged from 0 (newly diagnosed) to 17 years with current doses of prednisolone ranging from 0 mg to 50 mg (nine were off glucocorticoids). Most respondents agreed candidate instruments “good to go”. Approval: for pain measurement by VAS was given by 66.7% of participants and by 59.3% for NRS. Stiffness measured by VAS or NRS achieved 51.9% and 48.2% approval, respectively; and duration of stiffness 50%. Physical health as captured by HAQ-DI achieved 68.5% approval and mHAQ 53.3%. Furthermore, 56.3% of respondents agreed that CRP or ESR reflected disease activity in terms of levels of inflammation.ve themes were identified which patients felt were not covered adequately by the proposed instruments. These themes related to: (i) the variation, context and location of pain, (ii) the variability of stiffness, (iii) fatigue, (iv) disability, and (v) the variable correlation of inflammatory markers to their severity of symptoms.

Conclusion: The identified core domains and associated proposed candidate instruments were broadly acceptable to people with PMR. However, participants felt that there were gaps. The greatest concerns were for the proposed measures to capture the experience of stiffness, and that fatigue is missing altogether (although this is included as “important” rather than “core” for PMR). We plan to explore these issues in more depth with patients via cognitive interviewing. If outcome measures fail to capture adequately the impact of PMR on patients’ lives, then clinical trials of new treatments may be compromised.

Disclosures: M. Yates: None. C.E. Owen: None. S. Muller: None. K. Graham: None. L. Neill: None. H. Twohig: None. M. Boers: None. M.D.M. Pujades-Rodriguez: None. S. Goodman: None. J.T.L. Cheah: None. C. Dejaco: None. C. Mukhtyar: None. B. Dalsgaard Nielsen: None. J. Robson: None. L.S. Simon: None. B. Shae: None. S.L. Mackie: None. C. Hill: None.