“An Impediment to Living Life”: Why and How Should We Measure Stiffness in Polymyalgia Rheumatica?

To explore patients’ concepts of stiffness in polymyalgia rheumatica, and how they think stiffness should be measured.

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.

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 from carrying out “fundamental activities” and “generally living life”.  Diurnal variation instiffness was generally described in relation to the daily schedule but it was not the same as stiffness severity.  Some participants suggested measuring stiffness using a numerica rating scale of 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.