Conversion of the MDHAQ to the HAQ score: a simple algorithm developed and validated in a cohort of 13 391 real-world patients.

OBJECTIVES: To develop and validate in real-world patients a conversion algorithm from the Multidimensionel Health Assessment Questionnaire physical function scale (MDHAQ) to the Stanford Health Assessment Questionnaire disability index physical function scale (HAQ) score. METHODS: From the DANBIO registry, 13 391 patients with RA (n = 8983), PsA (n = 2649) and axial spondyloarthritis (axSpA, n = 1759) with longitudinal data on HAQ and MDHAQ were included, stratified by diagnosis, and randomized 1:1 into development and validation cohorts. Conversion algorithms were developed by linear regression and applied in validation cohorts. From MDHAQ, the HAQ was calculated (cHAQ) and validated against the observed HAQ for criterion, correlational and construct validity. RESULTS: For RA, we developed the conversion algorithm cHAQ = 0.15+MDHAQ*1.08, and validated it in the RA validation cohort. Criterion validity: HAQ and cHAQ had comparable discriminative power to distinguish between high and low patient global scores (standardized mean difference: HAQ:-1.29, cHAQ:-1.35). Kappa value between HAQ and cHAQ functional states indicated good agreement (0.83). Correlational validity: baseline HAQ and cHAQ, respectively, correlated well with patient global scores (r = 0.65/0.67). Bland-Altman plots showed good agreement across all functional states. Construct validity: HAQ and cHAQ discriminated equally well between patients reporting symptom state as acceptable vs not, and across responses to an external anchor. Aiming for a common algorithm, the RA conversion algorithm was validated for PsA and axSpA with similar results. CONCLUSION: This study suggests that in observational datasets with only the MDHAQ available, a simple algorithm allows valid conversion to HAQ on the group level in RA, PsA and axSpA.

Patients' Views on Routine Collection of Patient-Reported Outcomes in Rheumatology Outpatient Care: A Multicenter Focus Group Study.

OBJECTIVE: To explore the patients' views of the collection and use of patient-reported outcomes as part of routine care in patients with inflammatory arthritis. METHODS: We conducted a qualitative focus group study based on interviews in each of the 5 geographical regions of Denmark. The analysis was based on content analysis. Four patient research partners were involved in the study. RESULTS: In total, 32 adult patients (21 female) with rheumatoid arthritis (n = 21), psoriatic arthritis (n = 6), and axial spondyloarthritis (n = 5) participated. The mean age was 60 years (range 32-80 years). Five themes were derived from the analysis: 1) a need for information about why the data are collected, reflecting patients' uncertainty as to whether the collection of patient-reported outcomes primarily served to monitor their own disease, to save money, or to gather data for research purposes; 2) inclusion of patient-reported outcomes in the consultation, encompassing patients' expectations of active use of the patient-reported outcomes data during talks with rheumatologists or nurses; 3) reflections on how to respond to the patient-reported outcome measures (PROMs) to obtain high quality data, referring to patients' concerns about how to respond "correctly" and about issues that could affect their responses; 4) addressing patient-reported outcomes to the individual's challenges, reflecting the need for a more individualized approach; and 5) possibilities for improvement in the use of patient-reported outcomes, referring to patients' ideas for the future use of patient-reported outcomes. CONCLUSION: Information and dialogue regarding the purpose of patient-reported outcomes collection, how to respond to PROMs correctly, and inclusion of the patient-reported outcomes data in the consultation are of importance to patients with inflammatory arthritis who routinely complete patient-reported outcomes.