Objective  To investigate the delay of treatment in pulmonary tuberculosis (TB) patients in Inner Mongolia autonomous region from 2016 to 2020, identify the influencing factors and provide evidence for the formulation of pulmonary TB control measures and the reduction of treatment delay rate.

  Methods  The registration information of pulmonary TB patients in Inner Mongolia from 2016 to 2020 was collected from the National Health Security Information System. Median and quartile space description were used for statistical description, and the influencing factors of the treatment delay were analyzed by univariate and multivariate logistic regression models.

  Results  The median of treatment delay in the pulmonary TB patients was 32 (11, 67) days in Inner Mongolia from 2016 to 2020, the average annual treatment delay rate was 70.80% (36769/51933) and showed a downward trend (χ²=335.552, P<0.001). Univariate analysis showed that there were significant differences in the treatment delay rate among the patients in different ethnic groups, the patients in different age groups, the patients with different residence registration, the patients with different occupations, the patients with different case finding and diagnosis results (χ²=43.507, 166.956, 296.935, 566.818, 416.006, 30.997, all P<0.001), there were no significant differences in the treatment delay rate among the patients in different gender groups and treatment groups (P=0.419, 0.727). Multivariate logistic regression analysis showed that being ethnic minority, age >45 years (compared with age <25 years), being farmer/herdsman, being retirees, being jobless and unemployed (compared with students), case finding by referral, follow-up and others (compared with health examination and active screening) and positive etiological diagnosis were the risk factor for delayed treatment of pulmonary TB patients.

  Conclusion  The delay of treatment in pulmonary TB patients in Inner Mongolia was serious, so the prevention and control measures should be formulated to reduce the treatment delay rate according to relevant risk factors for the reductions of transmission risk and the incidence of TB.