Time delays and risk factors in the management of patients with active pulmonary tuberculosis: nationwide cohort study

Abstract

Estimating the time delay and identifying associated factors is essential for effective tuberculosis control. We systemically analysed data obtained from the Korea Tuberculosis Cohort in 2019 by classifying delays as presentation and healthcare delays of pulmonary tuberculosis (PTB). Of 6593 patients with active PTB, presentation and healthcare delays were recorded in 4151 and 5571 patients, respectively. The median presentation delay was 16.0 (5.0-40.0) days. Multivariable logistic regression analysis showed that longer presentation delays were associated with neuropsychiatric disease [adjusted odds ratio (OR) 2.098; 95% confidence interval (CI) 1.639-2.687; p < 0.001] and heavy alcohol intake (adjusted OR 1.505; 95% CI 1.187-1.907; p < 0.001). The median healthcare delay was 5.0 (1.0-14.0) days. A longer healthcare delay was associated with malignancy (adjusted OR 1.351; 95% CI 1.069-1.709; p = 0.012), autoimmune disease (adjusted OR 2.445; 95% CI 1.295-4.617; p = 0.006), and low bacterial burden manifested as an acid-fast bacillus smear-negative and tuberculosis polymerase chain reaction-negative status (adjusted OR 1.316; 95% CI 1.104-1.569; p = 0.002). Active case-finding programmes need to focus on patients with heavy alcoholism or neuropsychiatric diseases. To ensure early PTB detection, healthcare providers must carefully monitor patients with malignancy, autoimmune disease, or a high index of suspicion for PTB.

Figure 1

Flow diagram of the study. Among the patients with TB in the KTBC in 2019, those with EPTB without PTB were excluded. Patients diagnosed with PTB initially, but not true, were also excluded. Then, we classified the patients with PTB according to each study’s aim. First, to investigate presentation time delay and risk factors, patients without symptoms, with missing data, or with unrealistic time variables were excluded from the analysis. Second, to investigate healthcare time delay and risk factors, patients with missing data or unrealistic time variables were also excluded. Unrealistic time delay was defined as < 1 day of presentation and healthcare delay. Patients without symptom were identified as result of contact with a TB patient through the occupational and national health screening programme. Cases with unrealistic data were defined as the calculated delay was < 1 day. KTBC Korea Tuberculosis Cohort, EPTB extra-pulmonary tuberculosis, PTB pulmonary tuberculosis.

Figure 2

Definitions of each delay during the pulmonary tuberculosis diagnosis period. The overall delay was also measured. The median overall delay from the development of symptoms to the initiation of treatment for PTB was 27.0 (10.0–54.0) days. These parameters were estimated in 3965 patients using both presentation and healthcare delay data. We did not investigate the risk factors because of the complexity and heterogeneity of each delay. The histogram at the bottom of figure shows the frequency distribution for each time delay. IQR interquartile range.