Tuberculosis Care Quality Assessment: Evaluating Diagnosis and Treatment Effectiveness in Korea, 2018 to 2022
Article information
, Jinsoo Min,3, on Behalf of the Korean TB and NTM Research Group in The Korean Academy of Tuberculosis and Respiratory Diseases (KATRD)Abstract
Background
Tuberculosis (TB) care quality assessment has been implemented in the Republic of Korea since 2018. This paper evaluates the results of six rounds of the quality assessment from 2018 to 2023, focusing on the sixth quality assessment in 2023.
Methods
This study used cross-linked databases from the Health Insurance Review and Assessment Service, the Korea Disease Control and Prevention Agency, and the Ministry of the Interior and Safety. The study population included newly diagnosed TB patients reported between January and June each year from 2016 to 2023. The sixth quality assessment employed five indicators, which included the treatment success rate. Trends were analyzed using linear regression, and statistical comparisons were performed using chi-square tests.
Results
The sixth quality assessment demonstrated statistically significant improvements across all indicators. Since the fifth assessment, over 95% of patients diagnosed with respiratory TB have undergone TB confirmation tests. Both phenotype and molecular drug susceptibility test coverages showed significant upward trends since the third and fourth assessments, respectively. The treatment success rate, introduced for the first time in the sixth assessment, was reported at 78.3%. Non-TB-related deaths (10.3%) were the most common outcome, other than treatment success.
Conclusion
The TB care quality assessment has contributed to standardizing TB care in Korea and improving management indicators. Further efforts are needed to enhance treatment success through refining the evaluation criteria and implementing innovative management strategies.
Introduction
Tuberculosis (TB) is one of the most significant diseases impacting global public health. In 2023, TB posed a substantial threat to public health worldwide, an estimated 1.25 million deaths being attributed to the disease [1]. TB is an airborne infectious disease that is caused by Mycobacterium tuberculosis complex, and can be effectively treated through early diagnostic testing and consistent adherence to anti-TB medication regimens. TB requires meticulous management, because delays in diagnosis and treatment, together with the emergence of drug-resistant strains, significantly increase the risk of treatment failure and mortality, particularly among individuals with advanced age, multiple comorbidities, or social risk factors [2,3]. In the Republic of Korea, the incidence of newly diagnosed TB cases in 2011 to 2022 steadily declined from 78.9 to 39.8 per 100,000 population [4]. However among high-income countries, Korea still ranks second in TB incidence and fourth in TB-related mortality, highlighting the persistently high burden of the disease [1].
TB management in Korea is spearheaded by the Korea Disease Control and Prevention Agency (KDCA) through the third National Strategic Plan for Tuberculosis Control (2023 to 2027), with the objective of reducing the TB incidence rate to less than 20 cases per 100,000 population by 2027. As a key evaluation component of the national TB control program, TB care quality assessment is conducted under the leadership of the KDCA and the Health Insurance Review and Assessment Service (HIRA). The primary purpose of TB care quality assessment is to support the government’s TB eradication strategy by promoting standardized diagnosis for newly diagnosed TB cases, and reducing the initial transmissibility of TB bacteria, thereby lowering the incidence rate. This assessment also aims to enhance patient management and overall quality of care through a multifaceted approach. TB care quality assessment was first introduced in 2018 and has since been conducted annually. Continuous revisions and improvements of the evaluation indicators have contributed to their annual development and enhancement.
This study focuses on the sixth TB care quality assessment in 2023, and analyzes the evaluation results from 2018 to 2023 to identify key trends and outcomes, as well as proposed directions to improve evaluation indicators. By systematically assessing the impact of the TB care quality assessment on reducing TB incidence and enhancing patient management quality in Korea, this study aims to contribute to the development of a sustainable management framework for future TB eradication efforts.
Materials and Methods
1. Data source
The TB care quality assessment used data from the HIRA, KDCA, and Ministry of the Interior and Safety (MOIS) to comprehensively evaluate the appropriateness of TB care. The KDCA provided notification data of newly diagnosed TB cases notified between January and June each year, which were used to identify patients included in the denominator of the evaluation indicators. Subsequently, HIRA identified patients from the KDCA dataset using the unique insurance code for TB (V000), who had claims for hospitalization or outpatient care under the TB cost exemption policy. The evaluation indicators for this target population were then calculated. In addition, mortality data from the MOIS were incorporated to apply exclusion criteria for specific evaluation indicators. This multi-source data integration enabled a thorough assessment of the appropriateness of TB diagnosis, treatment, and management, enhancing the reliability and accuracy of the study results. Since its initial implementation in 2018, the evaluation has been conducted annually. As of 2025, results of the sixth quality assessment have been published.
2. Study population
The study population for the TB care quality assessment comprised newly diagnosed TB patients notified to the KDCA annually from January to June of each year between 2016 and 2023. The notified TB patients, who visited medical institutions where outpatient or inpatient claims with the unique insurance code for TB (V000) were recorded during the evaluation period—covering tertiary hospitals, general hospitals, hospitals, and clinics—were finally included in the analysis. Institutions where detailed medical records could not be verified due to fixed amount claims by HIRA, such as long-term care hospitals and public health centers, were excluded. Patients with multidrug-resistant TB (MDR-TB) or extensively drug-resistant TB were excluded from the analysis.
3. Evaluation indicators
The sixth TB care quality assessment included a total of five indicators that were categorized into four evaluation indicators and one monitoring indicator (Table 1). Since the fourth quality assessment in 2021, the indicators for adherence to initial standard regimen and patient’s hospital visit rates have been discontinued. The anti-TB drug prescription days rate was analyzed, excluding patients who died within 6 months of their TB diagnosis. A treatment success rate indicator was introduced in the sixth quality assessment. The TB treatment outcomes were defined according to the Korean Tuberculosis Guidelines, adopted from the World Health Organization (WHO) [5]. The definition of treatment success is the sum of cured, and treatment completed. Still-on-treatment was defined as cases with missing treatment outcome data, such as patients still undergoing treatment, or where data entry was incomplete.
Definitions of indicators and their numerator and denominator of the tuberculosis care quality assessment
4. Statistical analysis
Data are presented as numbers with percentages. Differences in evaluation indicators (test implementation rates) across years (evaluation cycles) and treatment success rates by institution type were analyzed using chi-square tests. Trends in evaluation indicators over time were assessed using linear regression to calculate the p for the trend. A statistical significance threshold (p-value) of less than 0.05 was applied for all analyses, which were performed using R statistical software version 4.1.2 (R Foundation, Vienna, Austria).
5. Ethics statements
This study protocol was approved by the Chung-Ang University Hospital Institutional Review Board (IRB) (IRB number 2502−001−19560). The requirement for informed consent was waived, because all participants were anonymized. This study was conducted in accordance with the amended Declaration of Helsinki.
Results
1. Patient characteristics
In the sixth TB care quality assessment, 505 institutions and 6,573 cases were included between January and June 2023, showing a decrease in both the number of institutions and cases compared to the first quality assessment, which included 620 institutions and 10,297 cases in 2018. General hospitals accounted for the highest number of cases (3,548 cases [54.0%], 12.2 cases per institution), while tertiary hospitals had the highest average number of cases per institution (2,642 cases [40.2%], 58.7 cases per institution). Public-private mix (PPM) project-participating institutions comprised 181 facilities (35.8%) and managed 5,530 cases (84.1%). Among the evaluated patients, 60.0% were male, while individuals aged 50 years or older accounted for 82.4%. Respiratory TB (A15−A16) constituted 87.2% of cases, while miliary TB (A19) accounted for 1.4%.
2. Tuberculosis confirmation testing coverage
TB confirmation tests, which include the acid-fast bacilli (AFB) smear test, AFB culture test, and nucleic acid amplification tests, are essential diagnostic tests to identify the M. tuberculosis complex. Up until the fourth evaluation, the rates for each test were measured individually. However, commencing with the fifth assessment, the indicator was revised to calculate the proportion of patients who underwent all three initial diagnostic tests. Since the fifth assessment, over 95.4% of patients diagnosed with respiratory TB have undergone TB confirmation tests. Although the TB confirmation test implementation rate appeared slightly higher in the sixth assessment than in the fifth assessment at 96.0% vs. 95.4%, the difference was not statistically significant (p=0.133) (Table 2).
Trends in tuberculosis confirmation testing coverages between 2018 and 2023
3. Phenotype and molecular drug susceptibility testing coverages
Table 3 presents the phenotype and molecular drug susceptibility testing (DST) coverages. The phenotype and molecular DST coverages represent the proportion of newly diagnosed respiratory TB patients (A15, A16, A19) with positive cultures who underwent each respective test. The molecular DSTs encompass Xpert MTB/RIF assay, line probe assay, and genome sequencing. The phenotype DST coverage has been measured since the third assessment in 2020 and shows a statistically significant upward trend in implementation rates (p for trend=0.037). Since the fifth assessment, the phenotype DST coverage exceeded 90.8%, with a statistically significant increase observed in the sixth assessment, compared to the fifth assessment at 90.8% vs. 92.9% (p=0.001) (Figure 1A). The molecular DST coverage has been measured since the fourth assessment in 2021. Although since its first introduction, its coverage has shown an upward trend, the trend was not statistically significant (p for trend=0.091). In the sixth assessment, the molecular DST coverage reached 90.7%, showing a statistically significant increase, compared to the fifth assessment at 85.9% vs. 90.7% (p<0.001) (Figure 1B).
Trends in phenotype and molecular drug susceptibility testing coverage between 2020 and 2023
The trend of drug susceptibility testing coverage by year; (A) phenotype test and (B) molecular test.
4. Tuberculosis drug prescription days rate/adherence to initial standard regimen/patient’s hospital visit rate
The adherence to the standard regimen and the patient’s hospital visit rate were indicators measured between the first and the fourth assessment. Since the first assessment, the adherence to the initial standard regimen consistently remained above 96.8%, with no statistically significant differences observed (p=0.485). The patients’ visit rate also remained stable, ranging 88.0% to 89.0%. The TB drug prescription days rate evaluates whether healthcare institutions maintain the standard 6-month prescription for drug-susceptible TB, as consistent medication adherence is critical to achieve a cure. Since its initial implementation, a consistently high TB drug prescription days rate of over 95.0% has been observed (Table 4).
Trends in tuberculosis drug prescription days rate, adherence to initial standard regimen, and patient’s hospital visit rate between 2018 and 2023
5. Treatment success rate
The treatment success rate is a newly introduced indicator in the sixth quality assessment and measures the proportion of newly diagnosed TB patients who achieved treatment success within 1 year from the date of TB diagnosis. The analysis was limited to patients who completed their treatment within a single healthcare institution. Among the 5,456 evaluated cases, 4,272 patients achieved treatment success within 1 year, yielding a treatment success rate of 78.3% in 2023 (Table 5). The treatment success rate was the highest (84.4%) in the clinics. Tertiary hospitals and general hospitals, which had the highest number of treatment cases, demonstrated treatment success rates exceeding 75.0%. There was no statistically significant difference in treatment success rates between the two types of institutions at 79.6% vs. 77.9% (p=0.139). Among the TB treatment outcomes other than treatment success, non-TB-related deaths (n=561, 10.3%) were the most common outcome, followed by still-on-treatment (3.4%), treatment success after 1 year (3.1%), and TB-related death (2.7%). Proportions of treatment success after 1 year (6.7%) and loss to follow-up (4.4%) were the highest in the clinics. Proportions of TB-related (14.3%) and non-TB-related (42.9%) deaths were the highest in the long-term care hospitals. Proportions of not evaluated (1.8%) and still-on-treatment (7.3%) were the highest in the hospitals.
Treatment success and other treatment outcomes of enrolled participants with tuberculosis in 2023 according to results of the sixth tuberculosis care quality assessment
Discussion
This study systematically analyzed the adequacy of TB management in Korea based on the sixth TB care quality assessment results and aimed to propose future directions to improve the national TB management system. The findings show that compared to the fifth assessment, all evaluation indicators in the sixth assessment demonstrated statistically significant improvements, confirming continued progress in TB care quality. In particular, after the third assessment, the phenotype DST coverage showed a significant upward trend, while after the fourth assessment, the molecular DST coverage continued to increase consistently. These findings indicate that standardized TB management has been effectively adopted in healthcare institutions. In addition, the sixth assessment introduced the treatment success rate for the first time, reporting a result of 78.3%. An additional evaluation of treatment success rate in future assessments is expected to serve as a foundation to improve the quality of TB management in Korea.
In Korea, the TB management indicators have remained consistently stable, even during the coronavirus disease 2019 (COVID-19) pandemic. After the WHO’s declaration of the pandemic in March 2020 [6], global medical priorities shifted towards the COVID-19 response. Globally, healthcare resources were heavily concentrated on the COVID-19 response, leading to the relative neglect of TB diagnosis and treatment services, as a consequence of their limited human and material resources. As a result, global TB management was adversely affected, ultimately contributing to an increase in TB-related mortality, and the expectation of further deaths in the long term [7-9]. To overcome these challenges, various strategies have been proposed through literature reviews following the COVID-19 pandemic, including strengthening latent TB infection management, maintaining national TB management services, and leveraging digital health technologies [10]. In Korea, TB management indicators showed improvement, even during the COVID-19 pandemic. This progress could be attributed to the sound performance of the PPM TB control project [11]. In 2022, 81.5% of newly registered TB cases in Korea were treated at PPM project-participating hospitals. However, Korea is one of the countries that effectively responded to the COVID-19 pandemic and successfully maintained its healthcare system, including the PPM project. In addition, despite the pandemic, the TB notification rate has been continuously decreasing since 2011. Continuous attention and support are necessary to maintain a robust TB management system in preparation for future pandemics. For this purpose, it is necessary to continuously conduct TB care quality assessment.
The TB care quality assessment indicators in Korea have been gradually added or discontinued, enhancing the overall evaluation system. Notably, since the fourth quality assessment, the indicators for adherence to the initial standard regimen and TB patient’s hospital visit rates have been discontinued. Adherence to the initial standard regimen, which is also one of the PPM monitoring indicators, had already been at a level that did not require further monitoring since the first assessment. Similarly, the hospital visit rates of TB patients were excluded, as the TB drug prescription days rate and treatment success rate could more directly reflect the effectiveness of TB management.
The treatment success rate, which was introduced in the sixth TB care quality assessment, serves as an important benchmark to evaluate the quality of TB treatment in Korea, relative to other countries. In 2022, the global average treatment success rate for TB patients receiving first-line therapy was 88%, with WHO regional estimates ranging from 72% in the Americas, to 93% in the Eastern Mediterranean region [1]. The TB treatment success rate in Korea was 78.3%, which was lower than the global WHO average. Although this study did not include age-stratified treatment outcome data, previous literature has suggested that countries with a rapidly aging population, such as Japan, which reported a treatment success rate of 65.4% in 2022 [12], may face additional challenges in managing TB, due to the higher rate of comorbidities and mortality among older adults [13,14]. In Korea, the relatively high mortality rate during TB treatment underscores the need for a systematic approach to reducing TB in the elderly through early diagnosis, active initial treatment, and comprehensive TB preventive treatment [15]. The higher TB treatment success rate at the tertiary and general hospitals with the presence of pulmonologists and TB specialists suggests that proactive treatment and management may contribute to reducing mortality among elderly people with TB.
Patients classified as ‘treatment success after 1 year’ or ‘unreported outcome (=still-on-treatment)’ were found to have experienced prolonged treatment durations due to interruptions or modifications in anti-TB medication caused by adverse drug reactions. For elderly patients, who are more susceptible to severe adverse effects from TB treatment, the development of novel drugs and treatment regimens with both tolerable safety profiles and improved therapeutic efficacy is essential [16].
It is worth noting that those who were transferred out were excluded in calculating the treatment success rate. Previous study revealed that a significant proportion of patients who transferred out to another TB unit did not receive additional TB care within 60 days, and were ultimately recategorized to the loss-to-follow-up category [17]. This implies that the treatment success rate in the sixth quality assessment could be over-estimated. In addition, despite decreased proportions of loss-to-follow-up since nationwide expansion of the PPM project in 2011, we still observe numerous cases of loss-to-follow-up and not-evaluated [18]. Because their treatment outcomes are difficult to assess and the risk of treatment disruption during the transfer process is high, dedicated management strategies are necessary for individuals with TB who plan to transfer out.
An integrated TB management system, including side effect management, treatment monitoring, and continuous care after transfer to another hospital, is essential. Artificial Intelligence technology is increasingly improving the ability to reduce drug-related adverse effects, and enhance TB diagnosis and management [19-21]. In addition, nutritional and psychosocial support programs for impoverished elderly patients are contributing to improving the quality of TB care for underserved populations [22,23]. Also, the WHO-approved video observed therapy has been shown to enhance medication adherence, compared to in-person observation [24]. These advances could contribute to improving TB treatment success rates and establishing a sustainable management system.
The seventh TB care quality assessment was conducted between January and June 2024, with the results expected to be published in October 2025. In the eighth assessment, which began in January 2025, the exclusion criteria have been further refined to ensure stricter evaluation of treatment indicators. The exclusion criteria were expanded from MDR-TB to rifampin-resistant TB. Foreigners who discontinued TB treatment due to repatriation and cases with mixed infections of TB and nontuberculous mycobacteria are now also excluded from the evaluation indicators. Through continuous refinement of the evaluation indicators, the TB management system could be further improved, ultimately contributing to the improvement of TB care quality, and the goal of TB elimination.
In conclusion, this study demonstrated improvements in TB management in Korea between 2018 and 2022, as evidenced by the enhanced evaluation indicators in the sixth TB care quality assessment. Sustained attention and support are crucial to maintain a strong TB management system, and conducting the TB care quality assessment on a continuous basis is essential to achieving this objective.
Notes
Authors’ Contributions
Conceptualization: all authors. Formal analysis: Gu KM. Data curation: Gu KM. Funding acquisition: Min J. Writing - original draft preparation: Gu KM. Writing - review and editing: all authors. Approval of final manuscript: all authors.
Conflicts of Interest
Jinsoo Min is an editor of the journal, but he was not involved in the peer reviewer selection, evaluation, or decision process of this article. No other potential conflicts of interest relevant to this article were reported.
Funding
This work was supported by the Research Program, funded by the Korea National Institute of Health (grant number 2022E200100). The funder had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.