SAT0592 MORTALITY AND CAUSE OF DEATH IN KOREAN PATIENTS WITH RHEUMATOID ARTHRITIS: BASED ON A LARGE COHORT.
Authors: Y. K. Lee, G. Y. Ahn, J. Lee, J. M. Shin, T. H. Lee, S. C. Bae
Journal: Annals of the Rheumatic Diseases (2020)

Background: Rheumatoid arthritis (RA) is a common chronic inflammatory disease characterized by arthritis of multiple joints. Although the use of corticosteroid and extra-articular complications may lead increased mortality of patients with RA and it have been confirmed by hundreds of studies, the prognosis of RA has improved over the past decades with the introduction of biologics disease-modifying anti-rheumatic drugs and treat-to-target strategy. Along with the increase of overall survival of RA, the needs for re-assessment of actual life expectancy in patients with RA have also been increased. Objectives: To investigate the cause and the risk of death of Korean patients with RA in a large RA cohort. Methods: We analyzed patients in Hanyang BAE RA cohort who fulfilled the American College of Rheumatology criteria. A total of 2,355 patients were enrolled from October 2001 to December 2015. Mortality data were derived by linking with data from the Korean National Statistical Office and date and cause death were identified. Standardized Mortality Ratio (SMR) was estimated by dividing the observed deaths by the expected number of deaths of age- and sex- matched general population. Confidence intervals were calculated based on the Poisson distribution. Table 1. Comparison of demographic and clinical characteristics of analyzed patients Total Died patients Survivors P value (n=2,355) (n=225) (n=2,130) Age at onset 41.8 ± 12.8 49.7 ± 12.7 41.0 ± 12.5 &lt;0.001 Age at enrollment 50.8 ± 12.3 63.3 ± 9.4 49.5 ± 11.8 &lt;0.001 Male 265 (11.3) 42 (18.7) 223 (10.5) &lt;0.001 Disease duration 18.1 ± 10.4 20.7 ± 10.9 17.8 ± 10.3 &lt;0.001 Observation period 9.0 ± 4.4 7.0 ± 3.6 9.2 ± 4.5 &lt;0.001 Smoking &lt;0.001 Never smoker 1,953 (83.9) 161 (74.9) 1,792 (84.8) Former smoker 212 (9.1) 36 (16.7) 176 (8.3) Current smoker 164 (7.0) 18 (8.4) 146 (6.9) Comorbidity Hypertension 330 (14.0) 63 (28.0) 267 (12.5) &lt;0.001 Diabetes mellitus 106 (4.5) 24 (10.7) 82 (3.9) &lt;0.001 *Values are number (%) or mean ± standard deviation. ** Missing data were excluded from analysis. Results: Over the observation period, 225 deaths were reported. The age at enrollment was 50.8 ± 12.3 years and disease duration was 18.1 ± 10.4 years. The most common cause of death was malignancy (40 cases) followed by respiratory disease (38 cases), cardiovascular disease (32 cases) and musculoskeletal disease (21 cases). Total SMR was increased [1.7, 95% CI 1.5-2.0] but age- and sex- adjusted SMR was not increased [SMR 1.0, (95% CI 0.9-1.1)]. When we classify patients by age conduct subgroup analysis, sex-adjusted SMR was also similar with that of general population by all group: the adjusted SMR in patients aged 15-39, aged 40-59 and aged over 60 were 0.7 (observed death 1, expected death 1.5, 95% CI 0-2.0), 0.9 (observed death 29, expected death 32 95% CI 0.6-1.3), and 0.9 (observed death 195, expected death 221.0, 95% CI 0.8-1.0), respectively. Compared with survivors, patients who died were more likely to be male (18.7% vs. 10.5%, p&lt;0.001) and they had an older age of onset of RA (49.7 years vs. 41.0 years, p&lt;0.001). Died patients were more likely to be current smoker or ever smoker (25.1% vs. 15.2%, p&lt;0.001) and accompanied by more comorbidities including hypertension (28.0% vs. 12.5%, p&lt;0.001) and diabetes mellitus (10.7% vs. 3.9%, p&lt;0.001). Conclusion: The overall age- and sex- matched SMR of patients with RA was similar with that of general population. However, compared with survivors, patients who died were more likely to be male, diagnosed with RA at older age, more likely to be smoker, and they have more hypertension and diabetes mellitus. Therefore, attention should be paid not only to RA itself but also managing comorbidities to improve the survival of patients with RA. Disclosure of Interests: None declared