AB1641 TOBACCO SMOKING HAS A PREVENTIVE EFFECT ON THE INCIDENCE OF KNEE OSTEOARTHRITIS: 10-YEAR RETROSPECTIVE COHORT STUDY BASED ON KOREA NATIONAL HEALTH INSURANCE SERVICE-HEALTH SCREENING DATABASE

Background Previous cross-sectional studies reported that smoking lowers the incidence of knee osteoarthritis, however, some show no correlation between and osteoarthritis. Thus relationship two has not been clarified [1,2]. To address this issue, we designed a retrospective cohort study to investigate association using large-scale claim database from Korea. best our knowledge, is first on osteoarthritis in Objectives We intended whether there was difference patients with history current smoking, past those without smoking. Methods The Korea National Health Insurance Service-Health Screening registered 98% Koreans includes all insurance claims. From database, observational conducted 316,387 adults who had undergone national health examination. Patients diagnosed prior examination were 2002 excluded. primary endpoint diagnosis operational definition code (M17) or any site (M15 M19) along x-ray (G720, G721) [3]. population followed day screening at index year date death, December 31, 2019, whichever comes first. Results patient group classified into non-smoker, ex-smoker, smoker groups according responses questionnaire. baseline characteristics each are included Table 1. 38.9%, 26%, 23% statistical significance (P-value < 0.001). When disease-free probability for presented Kaplan-Meier curve, it confirmed risk significantly different non-smoker as time passes (Figure 1, P-value Log-rank test hazard ratio 95% confidence intervals ex-smoker 0.95 (0.83-0.97), 0.89 (0.87-0.91). Conclusion This showed low smokers ex-smokers during follow-up period when compared non-smokers Additional required future. References [1]Zhang Y, et al. Relationship cigarette radiographic Chinese population: study. Rheumatol Int. 2015;35: 1211–1217. [2]Hui M, Does protect against osteoarthritis? Meta-analysis studies. Ann Rheum Dis. 2011;70: 1231–1237. [3]Park HR, Validation algorithms identify claims database. Int J 2019;22: 890–896. Baseline population. All subjects (n = 316,387) Non-smoker 187,116) Ex-smoker 65,290) Smoker 63,981) Demographics Age (years) 58.8 ± 9.0 58.2 8.5 56.5 7.8 0.001 Smoking (pack-years) 0.0 18.6 15.8 24.3 15.1 Underlying disease Hypertension (%) 60,840 (32.5) 20,466 (31.3) 17,488 (27.3) Diabetes 21,154 (11.3) 9,170 (14.0) 9,353 (14.6) Dyslipidemia 42,002 (22.4) 11,838 (18.1) 11,247 (17.6) Outcome Knee 72,778 (38.9) 16,963 (26.0) 14,715 (23.0) Figure K-M curve Acknowledgements: NIL. Disclosure Interests None Declared.