Stiffness Is the Cardinal Symptom of Inflammatory Musculoskeletal Diseases, Yet Still Variably Measured: Report from the OMERACT 2016 Stiffness Special Interest Group

J Rheumatol. 2017 Dec;44(12):1904-1910. doi: 10.3899/jrheum.161073. Epub 2016 Dec 15.

Abstract

Objective: The objectives of the Outcome Measures in Rheumatology (OMERACT) Stiffness special interest group (SIG) are to characterize stiffness as an outcome in rheumatic disease and to identify and validate a stiffness patient-reported outcome (PRO) in rheumatology.

Methods: At OMERACT 2016, international groups presented and discussed results of several concurrent research projects on stiffness: a literature review of rheumatoid arthritis (RA) stiffness PRO measures, a qualitative investigation into the RA and polymyalgia rheumatica patient perspective of stiffness, data-driven stiffness conceptual model development, development and testing of an RA stiffness PRO measure, and a quantitative work testing stiffness items in patients with RA and psoriatic arthritis.

Results: The literature review identified 52 individual stiffness PRO measures assessing morning or early morning stiffness severity/intensity or duration. Items were heterogeneous, had little or inconsistent psychometric property evidence, and did not appear to have been developed according to the PRO development guidelines. A poor match between current stiffness PRO and the conceptual model identifying the RA patient experience of stiffness was identified, highlighting a major flaw in PRO selection according to the OMERACT filter 2.0.

Conclusion: Discussions within the Stiffness SIG highlighted the importance of further research on stiffness and defined a research agenda.

Keywords: OMERACT; OUTCOME MEASUREMENT; STIFFNESS.

MeSH terms

  • Arthritis, Psoriatic / diagnosis*
  • Arthritis, Psoriatic / physiopathology
  • Arthritis, Rheumatoid / diagnosis*
  • Arthritis, Rheumatoid / physiopathology
  • Disease Progression
  • Humans
  • Inflammation / diagnosis*
  • Inflammation / physiopathology
  • Musculoskeletal Diseases / diagnosis*
  • Musculoskeletal Diseases / physiopathology
  • Polymyalgia Rheumatica / diagnosis*
  • Polymyalgia Rheumatica / physiopathology
  • Rheumatology
  • Severity of Illness Index
  • Symptom Assessment