Development and testing of candidate items for inclusion in a new rheumatoid arthritis stiffness patient-reported outcome measure.

Objective: To qualitatively develop and test a set of candidate items for a new RA stiffness patient-reported outcome measure (PROM) that capture the patient perspective. This is an essential first step in PROM development, prior to quantitative development, assessment and validation. Methods: Focus groups further examined the previously developed stiffness conceptual model and explored the patient perspective regarding stiffness assessment. Data were analysed using thematic analysis. An iterative process of item development was then performed by the expert study team of researchers, patients and clinicians, based on the two qualitative datasets and informed by measurement theory and guidelines. Finally, these candidate items were tested using formal cognitive interview methodology and subsequently refined. Results: Sixteen RA patients from the UK participated in focus groups. Data confirmed the conceptual model of the RA patient experience of stiffness and provided insight into stiffness assessment, including suggestions regarding patient-relevant stiffness assessment categories such as impact, location and timing. These data informed the development of 77 candidate stiffness PROM items, including multiple formats for some. Eleven RA patients participated in cognitive interviews. Minor changes were made to items to enhance understanding and 32 items were removed, resulting in 45 candidate PROM items. Conclusion: Rigorous qualitative methodology and considerable patient involvement has underpinned items for a new RA stiffness PROM with strong content validity. Crucially, patient involvement broadened assessment beyond early morning stiffness duration, which may address existing PROM limitations. Items are now suitable for quantitative item reduction, structural development of the final PROM and validation.

Stiffness is more than just duration and severity: a qualitative exploration in people with rheumatoid arthritis.

OBJECTIVE: Stiffness is internationally recognized as an important indicator of inflammatory activity in RA but is poorly understood and difficult to measure. The aim of this study was to explore the experience of stiffness from the patient perspective. METHODS: Semi-structured interviews conducted with 16 RA patients were analysed independently by researchers and pat.ient partners using inductive thematic analysis. RESULTS: Six themes were identified. Part of having RA identified stiffness as a normal consequence of RA, perceived as associated with disease-related aspects such as fluctuating disease activity, other RA symptoms and disease duration. Local and widespread highlighted stiffness occurring not only in joints, but also over the whole body, being more widespread during the morning or flare. Linked to behaviour and environment illustrated factors that influence stiffness, including movement, medications and weather. Highly variable captured the fluctuating nature of stiffness within and between patients and in relation to temporality, duration and intensity. Impacts on daily life emphasized the effect of stiffness on a range of domains, including physical function, quality of life, psychological well-being, activities of daily living and participation in work and leisure activities. Requires self-management detailed self-management strategies targeting both the symptom and its consequences. CONCLUSION: Patients' experiences of stiffness were varied, complex and not exclusive to the morning period. Importantly, stiffness was reported in terms of impact rather than the traditional measurement concepts of severity or duration. Based on these findings, further research is needed to develop a patient-centred measure that adequately reflects inflammatory activity.