OBJECTIVES:

This study aims to assess the cost-effectiveness of improving adherence in tuberculosis (TB) patients through the national TB program in South Korea by using a discrete-event simulation (DES).

METHODS:

A DES model, which is optimal for TB treatments as it reflects individual patients’ changing attributes and the prognosis over time, was built to estimate lifetime cost and quality-adjusted life-years (QALYs) in TB patients. Through simulation, we estimated costs and QALYs of adherent and non-adherent TB patients. To evaluate the cost-effectiveness of TB program, we set the population consisting of 25,400 TB patients and 78.91% of adherent patients among them, which is the proportion of adherent patients before TB program in South Korea. The total number was based on new TB patients in 2020. Through TB program spending the additional cost of $470 per patient, the proportion of adherent patients increased from 78.91% to 93%, which is the reported proportion of adherent patients after TB program. To evaluate the cost-effectiveness of TB program that increased adherence rate up to 93%, we simulated the following change of average costs and QALYs of total TB patients in response to the growing proportion of adherent patients and estimated the incremental cost-effectiveness ratio (ICER).

RESULTS:

As for TB patients in adherent and non-adherent group, an adherent patient gained an average of 0.02 QALYs compared with a non-adherent patient. Before and after the national TB program, rising adherence rate from 78.91% to 93% in TB patients, costs and QALYs increased from $2,785 to $2,952 and 13.27 to 13.28 and per person. Following ICER was $10,538/QALY and adherence intervention in TB program was cost-effective given $20,000 of threshold.

CONCLUSIONS:

Improvement of adherence to TB treatment could be considered cost-effective through the current TB program. Commitment programs to improve patients’ adherence can be helpful to manage TB nationwide.