# Multiple DMARD discontinuations in rheumatoid arthritis: how often and in what patients? Results from a national clinical RA register

## TL;DR

This study examines how often patients with rheumatoid arthritis stop multiple DMARD treatments and identifies patterns in patient characteristics.

## Contribution

The study provides new insights into the frequency and characteristics of multiple DMARD discontinuations in rheumatoid arthritis patients.

## Key findings

- 10% of newly diagnosed RA patients and 25% of those starting a first b/tsDMARD discontinued ≥2 b/tsDMARDs within 4.5 years.
- Discontinuation rates varied widely depending on the definition used, ranging from 0.3% to 25%.
- Patient characteristics of those discontinuing multiple DMARDs were largely similar across different definitions.

## Abstract

Multiple discontinuations of biologic (b-) or targeted synthetic (ts-) disease-modifying antirheumatic drugs (DMARDs) may indicate difficult-to-treat disease. We aimed to assess the occurrence of b/tsDMARD discontinuations in patients with rheumatoid arthritis (RA), specifically how this varies by definition, across patient subsets and over time.

Observational cohort study using data from the Swedish Rheumatology Quality Register on patients diagnosed with RA between 2010 and 2019. We identified three populations: (1) newly diagnosed (N=17 780), (2) initiating a first-ever DMARD (N=18 038) and (3) initiating a first-ever b/tsDMARD (N=8075). In each, we assessed the proportions and characteristics of patients fulfilling either of seven alternative DMARD discontinuation criteria (each encompassing a unique combination of number and type(s) of b/tsDMARD).

At 4.5 years of follow-up, 10% in populations (1) and (2), and 25% in (3), had discontinued ≥2 b/tsDMARDs with different modes of action. The proportions meeting each of the other six definitions ranged from 0.3% to 10% in (1) and (2), and 1% to 25% in (3). Regardless of definition or time, the characteristics of discontinuers across populations (1) through (3) remained largely similar.

Applying treatment discontinuation-based definitions to an unselected RA population identifies widely varying proportions of patients with largely similar characteristics. Quantitatively, treatment-based definitions, follow-up time and study population must be clearly specified; qualitatively, the specific definition may be less critical.