Cost-effectiveness of Expanding Syphilis Screening and Diagnosis under Thailand’s Universal Coverage Scheme
TL;DR
Extending screening to all high-risk Thais with high-risk behaviors increased the total costs but improved the unit-cost efficiency and was more cost-effective than targeting specific groups.
Abstract
Objectives: The existing syphilis screening approach is insufficient in lowering the overall incidence of syphilis within the population. The current approach falls short of the World Health Organization 2030 elimination benchmarks (congenital syphilis <50 per 100,000 live births and a 90% reduction in incidence). This study aims to evaluate the cost-effectiveness of expanding syphilis screening and diagnosis in Thailand and its budget implications. Methods: Decision tree models were developed to estimate the number of syphilis cases detected and determine associated healthcare costs. The analysis adopted the payer perspective (National Health Security Office), with the current Universal Coverage Scheme (UCS) targeted-screening practice as the base scenario. Inputs were drawn from national surveillance, program service data, published test-performance studies, and standard cost references. The evaluation compared Thailand’s current UCS screening package with an enhanced strategy that encompasses a broader population and incorporates rapid diagnostic tests in addition to the current laboratory-based treponemal serological assessments. The primary outcomes included the number of syphilis cases detected and the incremental cost-effectiveness ratio, defined as the additional cost per case detected. A five-year budget impact analysis from the 2022 base year was also conducted. Results: Expanding screening to all Thais with high-risk behaviors increased the total costs but improved the unit-cost efficiency and was more cost-effective than targeting specific groups. The cost per case detected was lowest for expanding to all high-risk Thais (19,870 Thai baht (THB); US$567), compared to current practice (22,064 THB; US$629) and prisoners-and-youth (20,549 THB; US$586). Overall, annual budget expenditure is projected to increase from 149 million THB (US$4.25 million) to 169 million THB (US$4.82 million). Public Health Recommendations: Extending screening to all high-risk Thais is more beneficial and cost-effective than restricting it to specific subgroups. We recommend integrating this strategy into existing routine disease-screening programs, such as HIV testing, to address HIV and syphilis together.