Session Title: Clinical Practice/Patient Care
Session Type: Abstract Submissions (ARHP)
The objective of this study was to estimate the minimal clinically important difference (MCID) of seven self-administered measures assessing fatigue in persons with systemic lupus erythematosus (SLE).
The respondents (n=51, women 98%, age 52.8 ± 12.1 years, disease duration 18.7 ± 13.6 years) met in groups sessions with six to nine participants. After initial self-assessment with the seven fatigue questionnaires (Chalder Fatigue Scale, Vitality from SF-36, Fatigue Severity Scale, Multidimensional Assessment of Fatigue, Multidimensional Fatigue Inventory, Functional Assessment of Chronic Illness Therapy – Fatigue, and a single numeric rating scale), each respondent had a minimum of five face-to-face discussions, all followed by an individual comparative assessment of his or her own level of fatigue (7-grade scale: Much More, Somewhat More, Little More, About the Same, Little Less, Somewhat less, Much Less). This method resulted in 260 contrasting assessments; MCIDs were first calculated using the paired differences and then established by a regression approach. Patients were offered the opportunity to provide additional free comments regarding the questionnaires.
In total seven group sessions was hold with the 51 respondents (98% women). Correlations with the raw fatigue score for the seven questionnaires and patients’ assessment of disease activity varied between 0.421 (p < 0.01) and 0.641 (p < 0.001). The self-reported disease activity and fatigue correlations of the patients varied between 0.504 and 0.562 (p<0.001 for all). No correlations were found between fatigue and age (r = -0.134–0.059) or fatigue and disease duration (r = -0.113–0.01).
The result was divided into contrast groups, based on the individual comparative assessment (the 7-grade scale). For most instruments, the mean paired difference followed a slope where the contrast groups represented a reasonable and increasing level of fatigue, compared to the neighboring contrast group. The mean paired difference for the patients scoring “about the same fatigue” ranged from 1.4 for Chalder Fatigue Scale fatigue scale to 3.4 for Functional Assessment of Chronic Illness Therapy – Fatigue. The means for the “about the same” groups were used to standardise the estimates. Except for the Chalder Fatigue Scale, the estimates for the MCID relative to ‘‘little less fatigue’’ tended to be smaller than those for ‘‘little morefatigue’’. The paired approach (contrast group: “Little more fatigue”) varied from 4.6 to 17.0, and the regression approach varied from 4.45 to 10.75. Estimates in the regression approach were consistently higher than in the paired model. The MCID estimates were least favorable for the single numeric rating scale. In the free comments section fewer respondents supported the use of the single-question measure compared to the other questionnaires.
Based on our results, all seven instruments are adequate for detecting clinically important differences of fatigue in patients with SLE. However, the use of a single-question measure was not supported by the MCID estimates or by comments from the respondents.
I. E. Lundberg,
E. M. Welin Henriksson,
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/minimal-clinically-important-difference-for-seven-measures-of-fatigue-in-patients-with-systemic-lupus-erythematosus-results-from-a-swedish-setting/