AUTHOR=Montes-Olivas Sandra , Ozten Yaz , Homer Martin , Turner Katy , Fairley Christopher K. , Hocking Jane S. , Tse Desiree , Verschueren van Rees Nicolas , Wong William C. W. , Ong Jason J. 

TITLE=Evaluating the impact and cost-effectiveness of chlamydia management strategies in Hong Kong: A modeling study

JOURNAL=Frontiers in Public Health

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.932096

DOI=10.3389/fpubh.2022.932096

ISSN=2296-2565

ABSTRACT=Objectives: To illustrate the epidemiologic and cost-effectiveness impact of shifting the focus from population-based screening toward a targeted management approach for genital chlamydia infection.
Design: Modelling study, implementing an individual-based, stochastic, dynamic network model. 
Setting: Hong Kong.
Population: A hypothetical sample network of 10,000 people with a partnership distribution based on Hong Kong’s sexually active population of reproductive age (age 18-49 years).
Interventions: In this study, we present several scenarios with different implementations of universal vs. targeted screening (based on partner numbers). We also explored the impact of [1] screening only, [2] screening plus expedited partner therapy, and [3] screening plus partner testing. 
Primary outcome measures: Change of chlamydia prevalence before and after implementing the different strategies. The cost-effectiveness analysis reports total direct cost from a health provider perspective, the QALYs gained, and incremental cost-effectiveness ratios (ICER). 
Results: In comparing the effects of universal screening only and targeted screening of the high-risk population, the mean prevalence during the tenth year of intervention was 2.75 ± 0.30% and 2.35 ± 0.21%, respectively (compared with 3.24 ± 0.30% and 3.35 ± 0.21% before the interventions, respectively). The addition of contact tracing to the latter targeted screening scenario reduces the mean prevalence during the tenth year of intervention to 1.48 ± 0.13% (compared with 3.31 ± 0.33% at baseline) in the best-case of testing before treatment and maximal contact-tracing effectiveness (40%). Overall, the most effective scenarios were those for which interventions focused on the high-risk population defined by the number of partners, with contact tracing included. The ICER for targeted screening with contact tracing at 20% and 40% efficiency was $4,634 and $7,219 per QALY gained, respectively (10-year time horizon). Expedited partner therapy did not significantly impact overall chlamydia prevalence and caused overtreatment.
Conclusions: Our study suggests that targeted screening with strengthened contact tracing efforts is the most cost-effective strategy to reduce the prevalence of chlamydia in Hong Kong.