Adherence and Associated Factors of Treatment Regimen in Drug-Susceptible Tuberculosis Patients

Sungho Bea; Hyesung Lee; Ju Hwan Kim; Seung Hun Jang; Hyunjin Son; Jin-Won Kwon; Ju-Young Shin

doi:10.3389/fphar.2021.625078

Adherence and Associated Factors of Treatment Regimen in Drug-Susceptible Tuberculosis Patients

Front Pharmacol. 2021 Mar 15:12:625078. doi: 10.3389/fphar.2021.625078. eCollection 2021.

Authors

Sungho Bea¹, Hyesung Lee¹, Ju Hwan Kim¹, Seung Hun Jang², Hyunjin Son³, Jin-Won Kwon⁴, Ju-Young Shin^{1

5}

Affiliations

¹ School of Pharmacy, Sungkyunkwan University, Suwon, South Korea.
² Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Hallym University Sacred Heart Hospital, Hallym University, Anyang, South Korea.
³ Department of Preventive Medicine, College of Medicine, Dong-A University, Busan, South Korea.
⁴ BK21 FOUR Community-Based Intelligent Novel Drug Discovery Education Unit, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, South Korea.
⁵ Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.

Abstract

Background: Adherence to tuberculosis (TB) drugs is one of the key aspects of global TB control, yet there is a lack of epidemiological evidence on the factors influencing adherence to TB drugs. Thus, this study aimed to explore the adherence and factors associated with adherence among TB patients in South Korea. Methods: We conducted a cohort study using a sampled national healthcare database from 2017 to 2018. Our study population included incident TB patients initiating quadruple or triple regimen who were available for follow-up for 180-days. Adherence was evaluated using the proportion of days covered (PDC): 1) adherent group: patients with PDC ≥80%; 2) non-adherent group: patients with PDC <80%. Kaplan-Meier analysis was conducted to calculate the median time-to-discontinuation in the study population. We calculated the adjusted odds ratios (aOR) with 95% confidence intervals (CI) to assess factors associated with adherence to TB drugs using logistic regression. Results: Of 987 patients, 558 (56.5%) were adherent and 429 (43.5%) were non-adherent, with the overall mean PDC of 68.87% (standard deviation, 33.37%). The median time-to-discontinuation was 113 days (interquartile range 96-136) in the study population. Patients initiating quadruple regimen were more likely to adhere in comparison to the triple regimen (aOR 4.14; 95% CI 2.78-6.17), while those aged ≥65 years (aOR 0.53; 95% CI 0.35-0.81), with a history of dementia (aOR 0.53; 95% CI 0.34-0.85), and with history of diabetes mellitus (aOR 0.70; 95% CI 0.52-0.96) were less likely to adhere to the drug. Conclusion: Approximately 45% of TB patients were non-adherent to the drug, which is a major concern for the treatment outcome. We call for intensified attention from the authorities and healthcare providers to reinforce patients' adherence to the prescribed TB drugs.

Keywords: adherence; claims database; discontinuation; drug-susceptible tuberculosis; nationwide study.