RESUMO
BACKGROUND: The Multidimensional Health Assessment Questionnaire (MDHAQ) is a patient-reported outcome (PRO) tool that includes the Routine Assessment of Patient Index Data 3 (RAPID3), an index that can be calculated at the point of care. The objective of this study was to perform psychometric analyses of MDHAQ/RAPID3 to study its measurement properties in systemic lupus erythematosus (SLE). METHODS: The MDHAQ was completed by 161 SLE patients in routine care, along with LupusPRO (a disease-specific PRO). The SLE disease-specific activity index (SELENA-SLEDAI) and damage (SDI) were assessed. Data from 70 patients with rheumatoid arthritis who had completed MDHAQ during their routine medical care were used as controls to compare the results of Physical Function (FN) domain exploratory factor analysis. Internal consistency reliability (ICR) for FN items was calculated using Cronbach's α. Validity of MDHAQ/RAPID3 was evaluated for content validity and construct validity. Responsiveness of the RAPID3 to changes in disease activity anchors was assessed. RESULTS: The ICR of the 10 physical function items on Cronbach's α was 0.88. Exploratory factor analysis revealed cross-loadings of three FN items. RAPID3 showed a strong correlation with LupusPRO health-related quality of life score (rho -0.68 (p < 0.001)), indicating convergent validity. RAPID3 scores did not correlate with disease activity indices or SDI. After adjustment for fibromyalgia status, a weak correlation with the Physician's Global Assessment (PGA) (rho = 0.31, p = 0.008) was noted. RAPID3 could differentiate between SLE patients based on flare status. RAPID3 was not responsive to changes in PGA, SELENA-SLEDAI or SELENA-Flare Index. CONCLUSIONS: MDHAQ/RAPID3 has fair reliability and validity in SLE.
RESUMO
OBJECTIVE: To evaluate the responsiveness of Lupus Impact Tracker (LIT) to changes in physician and patient disease activity assessments over time. METHODS: Available longitudinal data from routine patient care visits on LIT, physician assessed disease activity (physician global assessment (PGA), SELENA-SLEDAI score, SELENA Flare Index (SFI)), and patient-reported changes in systemic lupus erythematosus (SLE) health status were analyzed. Significant, clinically important change (worsening or improvement) in physician disease activity assessment or patient-reported SLE health status were judged using the following criteria: change of 0.3 on PGA, 4 on SELENA-SLEDAI, change in SFI status over time, and change of 2 in either direction in patient-reported SLE health status. Mixed model regression analysis was used to compare changes in LIT using the above criteria. RESULTS: There were 1184 observations with significant changes in physician disease activity or patient-reported measure for 182 patients' data across 1364 visits. Patients' mean (SD) age and SELENA-SLEDAI were 43.5 (13.2) years and 6.4 (7.3) respectively. LIT mean scores decreased by more than 3 with improvement in PGA (standardized response mean -0.26, p < 0.05), while it increased by more than 5 with worsening in SELENA-SLEDAI (standardized response mean 0.42, p = 0.01). Mean change in LIT of greater than ±3 was noted with change in SFI status (p < 0.05). Mean LIT score decreased by greater than 4 and increased by greater than 2 with patient-reported improvement and worsening in SLE health status respectively (p < 0.05). CONCLUSIONS: LIT is responsive to physician-assessed and patient-assessed changes in disease status. A mean LIT change of 2-4 may represent a significant clinical change in LIT. It is an effective tool that may be used by patients and physicians in tracking disease impact in SLE patients.