title: "An impediment to living life": why and how should we measure stiffness in polymyalgia rheumatica?
abstract: OBJECTIVE
  To explore patients' concepts of stiffness in polymyalgia rheumatica (PMR), and how they think stiffness should be measured.
  
  
  METHODS
  Eight focus groups were held at three centres involving 50 patients with current/previous PMR. Each group had at least one facilitator and one rapporteur making field notes. An interview schedule was used to stimulate discussion. Interviews were recorded, transcribed and analysed using an inductive thematic approach.
  
  
  RESULTS
  Major themes identified were: symptoms: pain, stiffness and fatigue; functional impact; impact on daily schedule; and approaches to measurement. The common subtheme for the experience of stiffness was "difficulty in moving", and usually considered as distinct from the experience of pain, albeit with a variable overlap. Some participants felt stiffness was the "overwhelming" symptom, in that it prevented them carrying out "fundamental activities" and "generally living life". Diurnal variation in stiffness was generally described in relation to the daily schedule but was not the same as stiffness severity. Some participants suggested measuring stiffness using a numeric rating scale or a Likert scale, while others felt that it was more relevant and straightforward to measure difficulty in performing everyday activities rather than about stiffness itself.
  
  
  CONCLUSIONS
  A conceptual model of stiffness in PMR is presented where stiffness is an important part of the patient experience and impacts on their ability to live their lives. Stiffness is closely related to function and often regarded as interchangeable with pain. From the patients' perspective, visual analogue scales measuring pain and stiffness were not the most useful method for reporting stiffness; participants preferred numerical rating scales, or assessments of function to reflect how stiffness impacts on their daily lives. Assessing function may be a pragmatic solution to difficulties in quantifying stiffness.
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, United Kingdom; NIHR-Leeds Musculoskeletal Biomedical Research Unit, Leeds, United Kingdom.
authors.forename: Sarah Louise
authors.initials: SL
authors.lastname: Mackie
authors.affiliation: Department of Rheumatology, Ashford and St Peter's NHS Foundation Trust, Chertsey, United Kingdom.
authors.forename: Rodney
authors.initials: R
authors.lastname: Hughes
authors.affiliation: Department of Rheumatology, Ashford and St Peter's NHS Foundation Trust, Chertsey, United Kingdom.
authors.forename: Margaret
authors.initials: M
authors.lastname: Walsh
authors.affiliation: PMRGCAuk Surrey, Chertsey, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Day
authors.affiliation: PMRGCAuk Surrey, Chertsey, United Kingdom.
authors.forename: Marion
authors.initials: M
authors.lastname: Newton
authors.affiliation: Department of Rheumatology, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
authors.forename: Colin
authors.initials: C
authors.lastname: Pease
authors.affiliation: Department of Rheumatology, University of Bristol, Bristol, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Kirwan
authors.affiliation: University of the West of England, Bristol, United Kingdom.
authors.forename: Marianne
authors.initials: M
authors.lastname: Morris
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007596:Joints / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011111:Polymyalgia Rheumatica / Q000473:pathology* / Q000523:psychology; D012720:Severity of Illness Index