Abstract
Objective
To study the impact of tumour necrosis factor-α inhibitor (TNFi) therapy on the use of non-steroidal anti inflammatory drugs (NSAIDs) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and axial spondyloarthritis (axSpA) in Iceland.
Method
This registry cohort study used data from the nationwide database on biologics in Iceland (ICEBIO) and the Icelandic Prescription Medicines Register on disease activity, and filled prescriptions for NSAIDs, to study the period from 2 years before to 2 years after initiation of a first TNFi. Five randomly selected individuals from the general population matched on age, sex, and calendar time for each patient served as comparators.
Results
Data from 940 patients and 4700 comparators were included. Patients with arthritis were prescribed 6.7 times more defined daily doses of NSAIDs than comparators (149 vs 22 per year). After TNFi initiation, NSAID use decreased to a mean of 85 DDD per year, or by 42% in RA, 43% in PsA, and 48% in axSpA. At TNFi initiation, the quintile of axSpA patients who used most NSAIDs reported significantly worse pain (mean ± sd 66 ± 21 vs 60 ± 23 mm), global health (70 ± 20 vs 64 ± 23 mm), and Health Assessment Questionnaire score (1.21 ± 0.66 vs 1.02 ± 0.66) than the other patients, whereas no significant differences were observed in the groups with peripheral arthritis.
Conclusion
Patients with inflammatory arthritides requiring TNFi therapy use more NSAIDs than matched comparators, and consumption decreased following TNF initiation. Patient-reported measures are not associated with high NSAID use in patients with peripheral arthritis.
Acknowledgements
We are grateful to all patients who regularly record their symptoms in ICEBIO and all rheumatologists in Iceland who are part of the ICEBIO group. The ICEBIO group comprises K Erlendsson, AJ Geirsson, G Grondal, B Gudbjornsson, T Jonsdottir, H Jonsson, TJ Love, BR Ludviksson, GB Reynisdottir, S Saevarssdottir, K Steinsson, G Tomasson, and A Vikingsson.
Authors’ contributions
OP, BG, and PSG created the initial design for the study. OP and BG collected the data, and OP linked the three databases, cleaned the data, and carried out statistical calculations. OP, TJL, JKW, MCK, and BG analysed the data. All authors revised the draft paper and approved the final version.
Disclosure statement
JKW has received Consultancy fees from AbbVie, Amgen, Celgene, Eli Lilly, and Novartis; and research support from AbbVie, Amgen, Eli Lilly, Novartis, and Pfizer (all unrelated to the present work). MCK has received unrestricted research grants from Pfizer and Roche (unrelated to the present work). BG has received lecture fees from Amgen and Novartis (unrelated to the present work). No potential conflicts of interest were reported by the remaining authors.
Data availability statement
Data are available upon reasonable request to the authors.
Ethical approval
Before data collection, ethical approval was obtained from the National Bioethics Committee of Iceland and the Data Protection Authority (VSN: 18-008).