Impact of different tuberculosis history at the onset of future multidrug-resistant tuberculosis: A large, retrospective, population-based cohort study

Objectives: The impact of tuberculosis (TB) history on the risk of multidrug-resistant tuberculosis (MDR-TB) is not yet fully understood. We aimed to identify the impact of different TB history at the onset of future MDR-TB. Methods: A large, retrospective, population-based cohort study was performed between 2005 and 2019. A multivariable Cox model was used to evaluate independent risk factors for MDR-TB for individuals with different previous TB history (PTBH), such as newly diagnosed TB history (NDTH) and re-treated TB history (RTH). Results: Overall, 12 172 individuals with PTBH were included in this study. The main impacts of different PTBH at the onset of future MDR-TB were as follows: (a) low family income, high-risk occupation, TB patients with severe infection, extended or shortened treatment course, 2H3R3Z3E3/4H3R3 and frequency of sputum culture were significantly linked to incident MDR-TB only in individuals with NDTH (P < 0.05); (b) passive mode of TB case finding, individualised treatment regimens, 3HRZES/6HRE, duration of pulmonary cavities, excellent frequency of chest X-ray examination and duration of negative sputum smear were significantly associated with incident MDR-TB only in individuals with RTH (P < 0.05); (c) age