Economic Cost of Non-Adherence to TB Medicines Resulting from Stock-Outs and Loss to Follow-Up in the Philippines
A key element of successful tuberculosis (TB) control programs is adherence to treatment, and this is a cornerstone of most international and national policies and guidelines. Non-adherence is often due to patient-related factors but can also be a result of provider issues, such as stock-outs of TB medicines. Non-adherence results in increases in the length and severity of illness, death, disease transmission, and drug resistance, all of which have economic consequences in terms of cost and loss of income for patients and their families and cost to the health system.
Non-adherence is commonly due to treatment interruption, which may be for short, intermittent periods (e.g., days) or for longer periods of weeks or months that may lead to complete discontinuation of treatment. Interventions to prevent treatment interruption are aimed at both patients and providers. On the provider side, actions include ensuring proper prescribing practices and management of side effects, providing good quality medicines, and preventing stock-outs. Actions on the patient side include interventions to encourage patients to continue treatment even when they feel better and use medicines as directed and to remove barriers, such as transport costs. These actions are believed to be a good investment, but the economic savings have not been clearly defined.
The Philippines is among 22 countries considered to have a high TB burden, including multidrug-resistant TB (MDR-TB). The Philippines DOH has an extensive TB program with Directly Observed Treatment Short Course (DOTS) for TB and DOTS-Plus for MDR-TB. In addition to DOTS, the DOH has strategies and procedures in place to ensure and improve treatment adherence, including patient compliance incentives and supply chain management system strengthening, both of which are challenging in a large, decentralized country where health care services are generally managed at the local level and stock-outs and loss to follow-up (LTFU) are common.
In recent years, NTP data and several studies have indicated problems with stock-outs of some TB medicines and LTFU. Both result in treatment interruption, which has an impact on the well- being of patients and their families, on the health system, and on society and the economy in general.
The purpose of this study was to estimate the morbidity and mortality impact and economic costs of non-adherence to TB medicines resulting from treatment interruption due to stock-outs or LTFU. This is expected to be helpful in promoting the benefits of investing in improving patient management and interventions to ensure the availability of good quality medicines and to encourage and aid in patient compliance.