A 5-Year Retrospective, Observational Study Assessing Rheumatoid Arthritis Disease Outcome Measures to Characterize Systemic Lupus Erythematosus Burden in the USA.

Abstract

We evaluated the use of rheumatoid arthritis (RA) disease measures in patients with systemic lupus erythematosus (SLE) in a US community-based rheumatology physician network over 5years. This retrospective, observational cohort study (GSK Study 213818) of patients with SLE utilized electronic medical records (01 January 2010-31 December 2019) from the United Rheumatology Normalized Integrated Community Evidence database. The index was the date of first SLE diagnosis recorded in the database; the observation period was 5years post-index. RA disease measures evaluated were: Pain Index, Multi-Dimensional Health Assessment Questionnaire (MD-HAQ), Patient Global Assessment (PtGA), Physician Global Assessment (PGA), Swollen Joint Count (SJC), Tender Joint Count (TJC), Routine Assessment of Patient Index Data 3 (RAPID3), Clinical Disease Activity Index (CDAI), Simplified Disease Activity Index (SDAI), and Disease Activity Score 28 (DAS-28). The number of patients with measures utilized, the score on each measure, and proportion of patients per disease activity category were assessed. Overall, 5990 patients with SLE were included. The most frequently used measures were Pain Index, SJC, TJC, MD-HAQ, PtGA, RAPID3, and PGA (cumulative use over Years 1-5: 23.9-71.3%). For all measures, frequency of use was lowest in Year 1, followed by a general increase from Year 1 to Year 5. Scores remained relatively stable for most measures, and the proportion of patients in remission or with low/moderate disease activity per RAPID3 increased. RA disease measure utilization in SLE was generally infrequent but increased over time. Pain Index and MD-HAQ were the most commonly applied cumulatively across 5years of follow-up. The rationale for the increased use of these measures in SLE over time requires further exploration. In the absence of a clinically applicable SLE-specific measure, the use of RA measures, for example in conjunction with SLE measures, may provide an alternative approach for measuring disease activity, representing an opportunity to improve patient outcomes.