Measurement of stiffness in patients with rheumatoid arthritis in low disease activity or remission: a systematic review

Abstract

BackgroundRecent qualitative research has shown that stiffness is an important symptom for patients to identify remission. However, it is unclear how to measure stiffness in low disease activity. This systematic review aims to summarise the existing literature on validity of patient reported outcomes to measure stiffness in RA low disease activity states, to aid the choice for a measurement instrument.MethodsAn extensive pubmed-search was undertaken, identifying measurement instruments for patient perceived stiffness used in low disease activity. Eligible studies reported on 1) stiffness as an outcome in relation to other core set measures, 2) development of a patient reported tool to measure stiffness, or 3) comparison of two different tools to measure aspects of stiffness, all in low disease activity.ResultsOf 788 titles, only two studies report on validity of stiffness measures within low disease activity. Morning stiffness (MS) is reported in 44 to 80% of patients in low disease activity. A difference of 40 to 60 minutes in duration until maximum improvement is observed between active and inactive patients. Severity of MS might discriminate better between high and low disease activity compared to measurement of duration of MS.ConclusionsThere is insufficient data on measurement of stiffness in the spectrum of low disease activity or remission.

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

“…A lack of content validity in current stiffness PROMs was indicated in recent qualitative work where patients described stiffness as more than just severity and duration and not exclusively experienced in the morning [20,21]. This contrasts with the most commonly used PROM assessments, which capture only morning stiffness severity or duration [25]. Given the apparent inconsistency between current stiffness assessment and the patient experience of this symptom, the aim of this study was to: 1) clarify and/or expand the proposed stiffness conceptual model and obtain patient views on assessment; 2) develop and then 3) qualitatively test a set of candidate items for a new RA stiffness PROM that captures the patient perspective and demonstrates appropriate content validity resulting from development in accordance with best practice guidelines [27][28][29].…”

“…While this had been suggested in previous qualitative work [20,21], the results presented here enabled confirmation and further elaboration of these suggestions in an approach that focused on the development of appropriate stiffness assessment. For example, while current stiffness PROMs capture morning stiffness duration or severity [25], RA patients describe stiffness as not exclusive to the morning [20,21] and in the current study expressed difficulties with responding to items that focus solely on this timeframe. Furthermore, the apparent multidimensional nature of stiffness identified in the conceptual model particularly the impact that stiffness has on patients' lives [20] was here identified as a relevant stem question category (Table 3), and challenges the narrow focus of current PROM items focusing on severity and duration alone.…”

“…4-option Likert scale (Not at all, A little, Quite a lot, Very much) 25 Has RA stiffness made it difficult to balance without physically supporting yourself? Please circle the number that best describes the severity of your RA stiffness over a usual week when you are not in a flare?…”

“…These included the 24 items presented in multiple formats and six current stiffness PROM items (Table 4) identified in the literature review [25,26]. Items were formatted into a paper questionnaire for further qualitative testing using cognitive interviews.…”

“…This is particularly relevant to determining remission in a clinical context as it has been suggested that MS is likely to affect patients being unable to meet the stringent ACR/EULAR Boolean remission criteria [24]. Yet both a systematic literature review of stiffness PROMs in the assessment of low disease activity or remission [25] and an update of that review across all disease activity states [26] concluded that there was insufficient evidence supporting current stiffness PROMs, no indication of which stiffness PROM to use, and that no current PROMs had been developed with patient involvement. This is a fundamental concern as PROM development guidelines state that the purpose of PROMs are to capture what is relevant to the population of interest [27].…”