Comparative persistence of anti-tumor necrosis factor therapy in ankylosing spondylitis patients: a multicenter international study

Abstract

Objective

To evaluate persistence on conventional DMARDs (cDMARDs) and anti-TNF therapies, and to identify potential determinants of discontinuation among individuals with ankylosing spondylitis (AS) living in Brazil and Quebec, Canada.

Methods

We conducted a cohort study of AS patients using health administrative data (2010–2015). One-year and 2-year persistence rates were assessed. Cox regression was used to identify potential determinants of therapy discontinuation.

Results

One-year persistence was less likely in Brazil for both anti-TNF and cDMARDs (Brazil: 62.1 and 30.7%, Quebec: 66.9 and 67.0%). The 2-year persistence rates were lower for both anti-TNF and cDMARD, but remained higher in Quebec (Brazil: 47.9 and 18.1%, Quebec: 51.5 and 53.5%). In multivariate Cox regression analysis, age, sex and comorbidities were associated with persistence in both countries. In Quebec, persistence did not differ between rural and urban regions or with socioeconomic status. While in Brazil, patients in regions with higher Human Development Index and those in cities with lower Gini index were less likely to discontinue therapy.

Conclusions

Canadian AS patients were more likely to persist on therapy compared to Brazilian patients, although rates were lower at 2 years in both countries. Socioeconomic disparity in persistence was found in Brazil, but not in Quebec.

Keywords:

• Ankylosing spondylitis
• anti-TNF agents
• conventional DMARDs
• medication persistence
• cohort

Transparency

Declaration of funding

The authors did not receive financial support for this study.

Declaration of financial/other relationships

FAA is a research scholar funded by the National Counsel of Technological and Scientific Development (CNPq/Brazil, process 302137/2016-5). ER has received funds and consulting fees from Janssen Inc. in the course of an unrelated study. These institutions did not play any role in the design, the data collection, or the analysis of the study.

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

FAA and ER designed the study, analyzed the data and drafted the manuscript; MRRS, AAGJ, RGP, HN extracted, prepared and analyzed the data; BG and MB were involved in the analysis and interpretation of the data; all authors revised the manuscript critically for intellectual content and did the final approval of the version to be published. All authors agree to be accountable for all aspects of the work.

Notes

1 SAS Institute Inc., Cary, NC, USA