Is screening and treating asymptomatic chlamydia and gonorrhoea among pregnant women cost-effective to prevent preterm birth and low birth weight in Botswana?

OBJECTIVES

We investigated the costs and cost-effectiveness of screening and treatment for Chlamydia trachomatis and Neisseria gonorrhoeae among asymptomatic pregnant women in Botswana to prevent preterm birth/low birth weight, compared with no microbiological screening.

METHODS

A health systems perspective and microcosting approach were used to estimate the costs of screening, treatment and partner treatment. Cost, epidemiological and effectiveness data were collected alongside the Maduo Study, a non-randomised cluster-controlled trial in Gaborone, Botswana evaluating the effect of C. trachomatis and N. gonorrhoeae screening on health outcomes among asymptomatic pregnant women and infants. We developed a decision tree to model a hypothetical cohort of 50 000 pregnant women receiving screening at first antenatal care and third trimester visits. We defined cost-effective as having an incremental cost per disability-adjusted life year (DALY) averted <$3625 (50% of Botswana's 2023 gross domestic product per capita).

RESULTS

The cost per person screened was US$23.67. Additional costs of C. trachomatis and N. gonorrhoeae treatment were US$3.44 and US$4.60, respectively. The total cost of implementing the intervention among 50 000 pregnant women would be US$2 363 665. Compared with the standard-of-care, we projected an incremental cost per preterm birth/low birth weight outcome averted of US$962.56. Screening and treatment for C. trachomatis and N. gonorrhoeae were projected to be cost-effective with an incremental cost per DALY averted of US$580.51. However, the incremental cost-effectiveness ratio (ICER) was highly uncertain in sensitivity analyses, and assumptions about intervention effectiveness were highly influential on the ICER.

CONCLUSIONS

Screening for C. trachomatis and N. gonorrhoeae infections has the potential to prevent serious adverse birth outcomes that contribute to childhood mortality, morbidity and high costs to the healthcare system. Additional research on the effectiveness of screening and treatment for these infections on preventing adverse birth outcomes is necessary to provide robust evidence that can inform cost-effectiveness analyses and decision-making.