Risk of tuberculosis and uptake rates of latent tuberculosis infection(LTBI) screening among clinical risk groups in South Korea: A nationwide population-based cohort study

<bold>Introduction:</bold> Expanding LTBI screening remains a challenge. This study aimed to investigate the TB risk among clinical risk groups with various morbid duration to establish a priority for LTBI screening. Method This retrospective cohort study included patients with high TB risk conditions identified between January 1, 2018(index date), and December 31, 2019, using the National Health Insurance Database and Korean National TB Surveillance System. Standardized incidence ratio (SIR) for TB and LTBI screening uptake rates were investigated in 2 groups with conditions either previously or newly diagnosed at index date. <bold>Result:</bold> 3,493,370 patients were enrolled. SIR of TB was higher in newly diagnosed group than in previously diagnosed group. The uptake rate of LTBI test was the highest in TNF-inhibitors group (93.2%, 7247/7775). In analysis of morbid duration-stratified SIR of TB, subgroups with the shortest morbid duration showed higher SIR except HIV group. The uptake rate of LTBI test was the highest in TNF-inhibitors group, while others were suboptimal. <bold>Conclusion:</bold> SIR of TB was higher in group with condition newly diagnosed than in those with condition previously diagnosed, in each group. Further high-risk group should be investigated. <fig><object-id>erj;64/suppl_68/PA1479/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>