NSAIDs vs bDMARDs: Sex Disparities in Treatment Initiation for Axial Spondyloarthritis

New research examining treatment initiation patterns among patients with axial spondyloarthritis (axSpA) has revealed significant sex-based disparities, shedding light on the process from diagnosis to therapeutic intervention. Although nonsteroidal anti-inflammatory drug (NSAID) usage predominated among patients with newly diagnosed axSpA compared with biologic disease-modifying antirheumatic drugs (bDMARDs), a closer look showed differences in treatment initiation timelines between male and female individuals, according to the findings published in Arthritis Care & Research.

Data from the IBM MarketScan Database spanning from 2013 to 2018 were utilized for the study, which aimed to evaluate sex differences in the time to initiation of NSAIDs or bDMARDs among patients with axSpA.

A total of 174,632 adult patients diagnosed with the rheumatic condition were included in the analysis. The time between axSpA diagnosis and the initiation of NSAIDs or bDMARDs was assessed. Adjusted HRs (aHRs) were calculated using survival analyses, and Cox proportional hazard models were employed to determine associations between sex and treatment initiation predictors.

Results showed that the average age at axSpA diagnosis was 48.2 years, with a female majority (65.7%) . Before diagnosis, 37.8% of patients had received at least 1 NSAID prescription. When analyzing those without at least 2 different prescription NSAIDs before diagnosis, women (32.9%) initiated NSAIDs earlier than men (29.3%; aHR, 1.14; 95% CI, 1.11-1.16).

For patients with a history of NSAID use (with ≥2 different prescription NSAID dispensations in the baseline period), 4.2% initiated bDMARDs while 77.9% continued NSAID therapy post diagnosis. The time to bDMARD initiation was longer for women compared with men (aHR, 0.61; 95% CI, 0.52-0.72), although bDMARD initiation was quicker among those with baseline NSAID use.

Throughout the baseline period, indicators of health care utilization revealed trends, according to the study. While the majority of patients had primary care physician visits, a smaller percentage had visited a rheumatologist, indicating potential delays in accessing specialized care. Furthermore, a significant proportion of patients had utilized urgent care or emergency department services, and a notable minority of patients had been prescribed DMARDs or opioids during this period, suggesting varied approaches to managing axSpA symptoms and disease progression.

“The decision to initiate a bDMARD in axSpA is complex for patients, physicians, and payers because of the high cost of these medications, as well as the requirement by many payers for prior authorization,” the researchers concluded. “In our study, females appeared more likely to continue NSAIDs use, and the time to initiate bDMARDs was longer for females than males. This emphasizes the need for additional research to determine whether low initiation rates of bDMARDs after treatment with 2 different prescription NSAIDs among females with a diagnosis of axSpA, compared to that among males, represents a missed opportunity to prevent disease progression and improve quality of life for this patient population.”

Reference

Shridharmurthy D, Lapane KL, Baek J, et al. Sex differences in time to initiate NSAIDs or bDMARDs among patients with axial spondyloarthritis. Arthritis Care Res (Hoboken). Published online March 27, 2024. doi:10.1002/acr.25332