Costs, Health Benefits, and Cost-Effectiveness of Chlamydia Screening and Partner Notification in the United States, 2000-2019: A Mathematical Modeling Analysis

Abstract

Background: Chlamydia remains a significant public health problem that contributes to adverse reproductive health outcomes. In the United States, sexually active women 24 years and younger are recommended to receive annual screening for chlamydia. In this study, we evaluated the impact of estimated current levels of screening and partner notification (PN), and the impact of screening based on guidelines on chlamydia associated sequelae, quality adjusted life years (QALYs) lost and costs.

Methods: We conducted a cost-effectiveness analysis of chlamydia screening, using a published calibrated pair formation transmission model that estimated trends in chlamydia screening coverage in the United States from 2000 to 2015 consistent with epidemiological data. We used probability trees to translate chlamydial infection outcomes into estimated numbers of chlamydia-associated sequelae, QALYs lost, and health care services costs (in 2020 US dollars). We evaluated the costs and population health benefits of screening and PN in the United States for 2000 to 2015, as compared with no screening and no PN. We also estimated the additional benefits that could be achieved by increasing screening coverage to the levels indicated by the policy recommendations for 2016 to 2019, compared with screening coverage achieved by 2015.

Results: Screening and PN from 2000 to 2015 were estimated to have averted 1.3 million (95% uncertainty interval [UI] 490,000-2.3 million) cases of pelvic inflammatory disease, 430,000 (95% UI, 160,000-760,000) cases of chronic pelvic pain, 300,000 (95% UI, 104,000-570,000) cases of tubal factor infertility, and 140,000 (95% UI, 47,000-260,000) cases of ectopic pregnancy in women. We estimated that chlamydia screening and PN cost $9700 per QALY gained compared with no screening and no PN. We estimated the full realization of chlamydia screening guidelines for 2016 to 2019 to cost $30,000 per QALY gained, compared with a scenario in which chlamydia screening coverage was maintained at 2015 levels.

Discussion: Chlamydia screening and PN as implemented in the United States from 2000 through 2015 has substantially improved population health and provided good value for money when considering associated health care services costs. Further population health gains are attainable by increasing screening further, at reasonable cost per QALY gained.

Figure 1

Cumulative number of sequelae outcomes averted by chlamydia screening. Shown as mean and 95% UI. (A) Sequelae averted by chlamydia screening and PN, 2000–2015*. (B) Sequelae averted by screening as indicated by the guidelines, 2016–2019**. (C) Sequelae averted by screening as indicated by the guidelines, 2016–2019 with the additional 5 years of follow up (2020–2024)**. Epid, epididymitis. Notes: *No screening and no physician-initiated PN compared with current policy (screening coverage and PN as estimated in the calibrated model). **Guidelines: all sexually active women aged 15 to 24 years are screened annually; for years 2020–2024 screening coverage as estimated in the model in 2015. Compared with current policy (screening uptake in year 2016 and beyond was assumed to be the same as the calibrated model estimate for 2015).

Figure 2

CEAC for the 3 scenarios performed. Figure show the percentage of simulations in which the cost per QALY gained was less than the given threshold. The lines present the 3 main scenarios: CEAC for 2000–2015 current policy compared with no screening & no PN*; CEAC for screening at guidelines level compared with current policy (2016–2019)**; CEAC for screening at guidelines level compared with current policy with additional 5 years of follow-up (2016–2019 + 5 years)**. Notes: *No screening and no physician-initiated PN compared with current policy (screening coverage and PN as estimated in the calibrated model). **Guidelines: all sexually-active women aged 15 to 24 years are screened annually; for years 2020–2024 screening coverage as estimated in the model in 2015. Compared with current policy (screening uptake in year 2016 and beyond was assumed to be the same as the calibrated model estimate for 2015).