OP0218 MORTALITY IN PATIENTS WITH PSORIATIC ARTHRITIS IN SWEDEN
Authors: S. Exarchou, D. DI Giuseppe, G. M. Alenius, E. Klingberg, V. Sigurdardottir, S. Wedrén, U. Lindström, C. Turesson, L. T. H. Jacobsson, J. Askling, J. K. Wallman
Journal: Annals of the Rheumatic Diseases (2021)

Background: In contrast to the increased mortality reported in other inflammatory diseases such as rheumatoid arthritis and psoriasis, prior mortality studies in psoriatic arthritis (PsA) have shown inconsistent results. Objectives: To compare all-cause mortality between PsA patients in Sweden and matched general population controls, and to describe cause of death distributions in the two groups. Methods: All individuals in Sweden with ≥1 main diagnosis of PsA (ICD-10: L40.5/M07.0-M07.3) from outpatient visits to rheumatology or internal medicine clinics at age ≥18 years (y) 2001-2017 were identified from the Swedish National Patient Register. Each case was matched to 5 general population controls based on sex, county and age in the year of the first registered arthritis diagnosis for the case. Cases and controls were followed from 1 Jan, 2007, or from first PsA diagnosis thereafter for index cases, until first occurrence of death (data from the Swedish Cause of Death Register), emigration or 31 Dec, 2018. Mortality was assessed overall, as well as stratified by sex (45% males) and disease duration (PsA diagnosis prior to 2007 [38% of cases] vs. 2007-2017), using matched Cox proportional hazard regression, or – in case the Cox assumption regarding proportionality did not hold – matched Breslow test. To account for potential PsA misclassification (in a previous validation study, 86% of 400 cases fulfilled PsA classification criteria), a sensitivity analysis was performed by randomly replacing 20% of cases with one of their own controls. Moreover, incidence rate ratios (IRR) of death were calculated overall and stratified by sex, disease duration and age. Finally, causes of death (from the Cause of Death Register) were described for PsA cases and controls. Results: Over the 12y follow-up, 3 121 deaths occurred among 33 036 PsA cases (268 402 person-years at risk) and 12 884 deaths among 161 144 controls (1 302 250 person-years), resulting in an increased mortality among the PsA cases (HR 1.11 [95%CI 1.07-1.16], p&lt;0.001, Figure and Table; sensitivity analysis HR 1.09 [1.05-1.14]). The increased mortality was seen mainly among female PsA cases and among cases with longer disease duration (Figure; Table). IRR:s of death were significantly increased for all ages except &lt;40y, with the numerically highest point-estimates for ages 40-49y and 50-59y (Table). Cause of death frequencies among the PsA cases/controls: cardiovascular disease 29/27%; diabetes mellitus 2.1/2.5%; chronic kidney disease 0.4/0.3%; infection 5.7/4.5%; chronic pulmonary disease 5.1/4.1%; malignancy 29/34%; suicide 2.3/2.0%; other 27/26%. Table 1. Mortality rates and incidence rate ratios PsA cases Population controls Number of deaths Person-years at risk Mortality rate* Number of deaths Person-years at risk Mortality rate* Incidence rate ratio (95%CI ) Overall 3 121 268 402 11.6 12 884 1 302 250 9.9 1.18 (1.13-1.22) Males 1 459 120 517 12.1 6 468 580 285 11.1 1.09 (1.03-1.15) Females 1 662 147 886 11.2 6 416 721 966 8.9 1.27 (1.20-1.34) Longer disease duration 1 943 139 379 13.9 7 459 670 174 11.1 1.25 (1.19-1.32) Shorter disease duration 1 178 129 023 9.1 5 425 632 077 8.6 1.06 (1.00-1.13) Age intervals (years ) &lt;40 18 33 568 0.5 98 163 278 0.6 0.89 (0.54-1.48) 40-49 90 50 552 1.8 322 246 955 1.3 1.37 (1.08-1.73) 50-59 280 65 820 4.3 1 131 321 730 3.5 1.21 (1.06-1.38) 60-69 723 70 224 10.3 3 132 341 587 9.2 1.12 (1.04-1.22) 70-79 960 37 232 25.8 4 160 178 909 23.3 1.11 (1.03-1.19) ≥80 1 050 11 007 95.4 4 041 49 791 81.2 1.18 (1.10-1.26) * Per 1000 person-years. Conclusion: In this nationwide 12y assessment, the mortality risk among PsA patients in Sweden was increased by around 10% as compared to the general population, mainly driven by increased risks among females and patients with longer disease duration. Cause of death distributions were numerically similar between PsA cases and controls. References: Disclosure of Interests: Sofia Exarchou Consultant of: AbbVie, Novartis, Daniela Di Giuseppe: None declared, Gerd-Marie Alenius: None declared, Eva Klingberg Speakers bureau: Eli Lilly, Consultant of: Novartis, Grant/research support from: Roche, Valgerdur Sigurdardottir Consultant of: Novartis, Sanofi, Sara Wedrén: None declared, Ulf Lindström: None declared, Carl Turesson Speakers bureau: AbbVie, BMS, Pfizer, Roche, Consultant of: Roche, Grant/research support from: BMS, Lennart T.H. Jacobsson Consultant of: AbbVie, Eli Lilly, Janssen, Novartis, Pfizer, Johan Askling Grant/research support from: For ARTIS: AbbVie, BMS, Eli Lilly, Merck, Pfizer, Roche, Samsung Bioepis, Sanofi, UCB. This study was supported by AbbVie, Amgen, Eli Lilly, Novartis and Pfizer. The sponsors were allowed to comment on the study protocol and were provided with a report of the results, but had no influence on the study design or decision to submit the abstract., Johan K Wallman Consultant of: Celgene, Eli Lilly, Novartis