Risk factors associated with tuberculosis recurrence in South Korea determined using a nationwide cohort study

Abstract

Objective Prevention of tuberculosis (TB) recurrence is an important issue in TB control. South Korea, a country with a high average income, has been challenged with an intermediate burden of TB. We aimed to estimate the TB recurrence rate after successful completion of the first anti-TB chemotherapy, and to identify the risk factors for the TB recurrence by focusing on co-morbidities and behavioral factors. Methods This is a population-based cohort study using data from the National Health Insurance (NHI) database between 2002 and 2013. Newly diagnosed TB patients were identified using the classification of disease codes and prescription records. Final analytical subjects included people who successfully completed the first anti-TB chemotherapy. The primary outcome measure was recurrent TB 6-month after the first treatment completion. A set of associated risk factors, including demographic characteristics, co-morbidities, and health behavior factors were analyzed using Cox regression analysis. Results Among 5,446 TB patients, 2,226 (40.1%) completed the first anti-TB treatment. During the follow-up period, 150 (6.7%) patients had TB recurrence, and the crude recurrent rate was 22.6 per 1000 person-years. The majority of recurrence cases (89%) occurred within the first 2-year period. The major findings show that participants who are male (adjusted HR (aHR) = 1.81, at a 95% CI, range: 1.11–2.94), older in age (aHR = 1.07, at a 95% CI, range: 1.00–1.14), have a lower income (aHR = 1.96, at a 95% CI, range: 1.10–3.48) and who are underweight (aHR = 1.92, at a 95% CI, range 1.15–3.20) were at higher risks for TB recurrence. Conclusion People who have risk factors for recurrent TB need to improve treatment compliance through more effective TB management, and follow-up observation for one or two years after the treatment completion.

Recurrence Rate of Pulmonary Tuberculosis in Patients Treated with the Standard 6-Month Regimen: Findings and Implications from a Prospective Observational Multicenter Study

“…However, the TB recurrence rate in this study was lower than the recurrence rate reported in some other studies in the literature. Youn et al (2022) reported a recurrence rate of 6.7% in Korea in a nationwide cohort study during 2002–2013 [ 13 ]. Ruan et al 2022 reported a 5-year recurrence rate of 5.4% in Hangzhou, China [ 15 ].…”

“…Ruan et al, in their 2022 study, indicated that more than half of TB recurrences (51.1%) occurred within one year of treatment completion [ 15 ]. Furthermore, it was reported that most recurrences (89%) happened within the first 2 years [ 13 ]. Another study showed that more than half of the recurrence cases (55.2%) occurred in the first 2 years after treatment completion [ 21 ].…”

“…The recurrence of TB following successful treatment is considered one of the main challenges posed to TB control in many countries. It is evident that even after successfully treating this infectious disease, individuals with a previous history of TB infection are at a higher risk of recurrent TB [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Moreover, the rate of TB recurrence differs widely among countries and regions [ 13 ].…”

“…It is evident that even after successfully treating this infectious disease, individuals with a previous history of TB infection are at a higher risk of recurrent TB [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Moreover, the rate of TB recurrence differs widely among countries and regions [ 13 ]. A meta-analysis showed that the pooled incidence rate of recurrent TB was 1.47 per 100 person-years in low-TB-burden settings compared to 4.10 per 100 person-years in high-TB-burden settings [ 16 ].…”

“…Many factors contribute to the variances in the rate of recurrent TB. These include the differences in study designs and characteristics (e.g., sample size, duration of follow-up) [ 13 , 16 , 21 ], the definition of TB recurrence in the studies [ 13 , 21 , 22 ], the TB burden in the country/region (high versus low prevalence of TB) [ 13 , 14 , 16 ], the study population and risk factors (e.g., comorbidities, HIV, diabetes, sociodemographic factors, smoking status) [ 21 , 23 ], the clinical characteristics of TB (e.g., presence of pre-treatment pulmonary cavities, sputum positivity after 2 months of treatment) [ 15 , 21 , 24 ], an anti-Tb drug regimen [ 16 , 17 , 25 ], and poor adherence to anti-tuberculosis drugs [ 17 , 23 ].…”