Measurement properties of the PolyMyalgia Rheumatica Activity Score (PMR-AS): a systematic literature review.

Abstract

To perform a COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) based Systematic Literature Review of measurement properties of the Polymyalgia Rheumatica Activity Score (PMR-AS). Pubmed, EMBASE, and CINAHL were broadly searched. English full text articles, with (quantitative) data on at least 5 PMR patients using the PMR-AS were selected. Seven hypotheses for construct validity and three for responsiveness, concerning associations with erythrocyte sedimentation rate, physical function, quality of life, clinical disease states, ultrasound, and treatment response, were formulated. Articles usable to assess - COSMIN based - structural validity, internal consistency, reliability, measurement error, or hypotheses on construct validity or responsiveness were selected and assessed based on COSMIN criteria. From the 26 articles using the PMR-AS we were able to use 12 articles. Structural validity, internal consistency, construct validity, and responsiveness were assessed in one, two, eight, and three articles respectively. Insufficient evidence was found to confirm structural validity and internal consistency. No data was found on reliability or measurement error. Although 60% and 67% of hypotheses tested for construct validity and responsiveness were confirmed respectively, there was insufficient evidence to meet criteria for good measurement properties. Whilst there is some promising evidence for construct validity and responsiveness of the PMR-AS, it is lacking for other properties and overall falls short of criteria for good measurement properties. Therefore, further research is needed to assess its role in clinical research and care.