Use of a “critical difference” statistical criterion improves the predictive utility of the Health Assessment Questionnaire-Disability Index score in patients with rheumatoid arthritis

Abstract

BackgroundThe Health Assessment Questionnaire-Disability Index (HAQ-DI) is used to assess functional status in rheumatoid arthritis (RA), but the change required for meaningful improvements remains unclear. A minimum clinically important difference (MCID) of 0.22 is frequently used in RA trials. The aim of this study was to determine a statistically defined critical difference for HAQ-DI (HAQ-DI-dcrit) and evaluate its association with therapeutic outcomes.MethodsWe retrospectively analyzed data from adult German patients with RA enrolled in a multicenter observational trial in which they received adalimumab therapy at the decision of the treating clinician during routine clinical care. The HAQ-DI-dcrit, defined as the minimum change that can be reliably discriminated from random long-term variations in patients on stable therapy, was determined by evaluating intra-individual variation in patient scores. Other outcomes of interest included Disease Activity Score-28 joints and patient-reported pain and fatigue.ResultsThe HAQ-DI-dcrit was calculated as an improvement (decrease) from baseline of 0.68 in a discovery cohort (N = 1645) of RA patients on stable therapy and with moderate disease activity (mean DAS28 [standard deviation] of 4.4 [1.6]). In the full patient cohort (N = 2740), 22.1% of patients achieved a HAQ-DI-dcrit improvement at month 6. Compared with patients with a small improvement in HAQ-DI (decrease of ≥0.22 to < 0.68) or no improvement (< 0.22), patients achieving a HAQ-DI-dcrit at month 6 had better therapeutic outcomes at months 12 and 24, including stable functional improvements. Change in pain was the most important predictor of HAQ-DI improvement during the first 6 months of therapy.ConclusionsA HAQ-DI-dcrit of 0.68 is a reliable measure of functional improvement. This measure may be useful in routine clinical care and clinical trials.Trial registrationClinicalTrials.gov NCT01076205. Registered on February 26, 2010 (retrospectively registered).

Mobile App-based documentation of patient-reported outcomes — 3-months results from a proof-of-concept study on modern rheumatology patient management

“…To detect differences of paper-based PROMs and ePROMs, we tested for equivalence (“two one-sided tests” (TOST) procedure). Reported minimal clinically important differences (MCIDs) of the PROMs were used for upper and lower equivalence bounds (HAQ: 0.22 for RA in clinical trials and RADAI: 1.49) [ 20 , 21 ]. Kruskal Wallis tests were performed for further group comparisons.…”

The Safety and Effectiveness of Infliximab Biosimilar in Managing Rheumatoid Arthritis: A Real-Life Experience from Jordan

“…This finding could be attributed to the high health risks in our cohort, such as the high body mass index (BMI), long disease duration, and high baseline DAS28 score in our patients. These factors were recognized as negative predictors for improvement in HAQ-DI scores over six months [ 41 ]. In addition, we could not exclude the floor effect in which patients with low baseline HAQ-DI scores cannot achieve significant decreases in HAQ-DI despite observed clinical improvements [ 35 , 41 ].…”

Intestinal microbiota changes induced by TNF-inhibitors in IBD-related spondyloarthritis

“…41 The improvement in HAQ-DI was defined as a minimum clinically important difference of 0.22. 42 Responders in the HBI for CD were defined by a decrease in the HBI score greater than or equal to 2 (or HBI ≤4 at 6 months), corticosteroid-free therapy. For patients with UC remission was defined as the reduction of the pMAYO 43 by at least two points, or final score ≤1, in the absence of corticosteroids.…”