Economic Assessment of Reverse Algorithm Syphilis Screening in a High Prevalence Population

Area of Science:

• Public Health
• Infectious Disease
• Laboratory Science

Background:

• Increasing use of automated treponemal immunoassays for syphilis screening.
• Comparison of traditional (nontreponemal) vs. reverse (treponemal) screening algorithms.
• Evaluation of direct costs and downstream consequences of algorithm change.

Purpose of the Study:

• To compare the cost-effectiveness of a reverse syphilis-screening algorithm versus a traditional algorithm.
• To analyze costs from the perspective of a public health laboratory and STD program.
• To assess the impact on syphilis case detection.

Main Methods:

• Decision analysis model utilizing laboratory and surveillance data.
• Cost-effectiveness estimation in 2015 US dollars.
• Perspective: Los Angeles County Public Health Laboratory and Department of Public Health.

Main Results:

• Reverse algorithm detected 626 additional syphilis cases (9.7% increase).
• Incremental cost-effectiveness ratio: $39 per additional case detected (Public Health Department perspective).
• Key cost drivers: follow-up, screening test costs, positivity rates, repeat infections.

Conclusions:

• Reverse algorithm slightly more expensive for the Department but identified more syphilis cases.
• Reverse algorithm resulted in lower overall laboratory costs.
• Algorithm choice impacts public health syphilis surveillance and cost-efficiency.