Diagnostic Delay Among Pulmonary Tuberculosis Patients Before, During and After COVID-19 Pandemic in Yichang City, China: A Longitudinal Study Based on Tuberculosis Surveillance Data

OBJECTIVES: Early diagnosis of pulmonary tuberculosis (PTB) is essential for individual case treatment and community transmission control. However, the impact of the COVID-19 pandemic on PTB diagnosis remains inadequately understood. In this study, we aimed to investigate the diagnostic delay in patients with PTB before, during and after the COVID-19 pandemic. METHODS: We conducted a longitudinal study of PTB in Yichang City from 2005 to 2023, utilizing data from the Tuberculosis Information Management System of China. The distribution of diagnostic delay (DD) was analyzed across three periods: pre-pandemic, during the pandemic, and post-pandemic. Multivariate mixed-effects logistic regression models were employed to identify factors associated with prolonged DD, defined as a delay exceeding 28 days. RESULT: A total of 58,774 patients with PTB were included in this study. The average annual number of cases was 3,293 pre-pandemic, 2,319 during the pandemic, and 2,426 post-pandemic. The fitted median DD in the pre-pandemic period (31.7 days, interquartile range [IQR] = 13.8-72.8) was significantly longer than that in the pandemic period (23.8 days, IQR = 11.3-50.3) and the post-pandemic period (20.6 days, IQR = 9-47.1) (p < 0.01). Elder patients aged 65 years and older had a longer median DD (32 days, IQR = 14.2-72.0) than patients aged 18-64 years (median: 30.1 days, IQR = 13.1-68.9) and patients under 18 years (median: 19.5 days, IQR = 8.6-44.2) (p < 0.01). Patients residing in rural areas also had a longer median DD (31 days, IQR = 14.2-72.0) compared to those in urban (median: 29.4 days, IQR = 13.7-70.2) (p < 0.01). Older age (adjusted Odds Ratio [aOR] = 2.20, 95% confidence interval [95% CI] = 2.00-2.42), rural residence (aOR = 1.10, 95% CI 1.06-1.14), positive pathogen testing (aOR = 1.35, 95% CI 1.23-1.49), and retreatment status (aOR = 1.23, 95% CI 1.16-1.31) were significantly associated with prolonged DD. Diagnosed by Xpert MTB/RIF (aOR = 0.71, 95% CI 0.65-0.78) was associated with a shorter DD. CONCLUSIONS: Compared to the pre-pandemic period, the overall interval from the onset of symptoms to the diagnosis of PTB patients shortened during and post-COVID-19 pandemic. Additional improvements in early diagnosis are needed for elderly patients and rural residents through the use of reliable diagnostic methods.