Consistency of Morning Stiffness: An Analysis of Diary Data

Abstract

This study aimed to determine the within-individual daily variation in morning stiffness (MS) of RA patients, and to validate the routine clinically derived duration of MS against that recorded prospectively by patients. Forty-nine RA patients, who during a detailed clinical interview reported experiencing MS that week were studied. They were asked to prospectively record, using a diary, daily information on the duration of their MS. The times both of waking and of getting up were noted, as well as the times to first improvement, maximum improvement and complete disappearance of MS, providing six possible estimates of MS duration, three of which, using waking as starting points, could be compared with the interview. The daily variation of MS was assessed by the within-patient range. The median duration of the diary scores was then compared with the MS estimates recorded at the interview. There was a large intra-individual variation in duration of MS, whichever of the six definitions were used. Half of the patients recorded ranges of MS scores of 3 h or more within the same week. There was also marked variation between the median diary derived duration and that ascertained by interview. This variation was at its smallest when the duration of MS was calculated as time until maximum improvement. The routine recording of the 'typical' duration of MS seems to have little clinical value in the face of the large within-patient variation. Of the possible choices for estimating duration, the time from waking to maximum improvement appeared to be the best indicator of the average duration of MS in RA patients.

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

“…Several studies provide evidence for validity of both duration as well as severity scales to measure stiffness, as both generally show good correlation with core set measures (especially pain and function) [19-22,27,28,30]. However, problems arise when these measures are used to discriminate RA from non-inflammatory conditions or osteoarthritis [12,24,26,31].…”

“Stiffness Has Different Meanings, I Think, to Everyone”: Examining Stiffness From the Perspective of People Living With Rheumatoid Arthritis

“…Morning stiffness duration is the most common, yet there are no standardized duration measures (15). Indeed, “morning stiffness” has been included in screening tools for inflammatory arthritis (16), and therapeutic agents that reduced early morning stiffness duration were approved for RA (17).…”

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

“…Poor content validity of current stiffness items may explain the inadequate psychometric performance of these items reported in the literature [6][7][8][9][10]. It also may explain the challenges reported with current items including that patients find completing duration items difficult, are often forced to report a cut-off time [48], and that patients have sometimes reported that they have no stiffness in a leader question asking about stiffness duration, only to later quantify the severity of that non-existent stiffness in a follow-up question [49]. This further supports the need for the involvement of the relevant population in the development of PROMs to enhance content validity and ensure that the patient experience is captured in outcome assessment.…”