Background: In response to the rising threat of resistance to first-line antibiotics for gonorrhea, international guidelines recommend dual antimicrobial therapy. However, some countries continue to recommend monotherapy. We assess the cost-effectiveness of dual therapy with ceftriaxone and azithromycin compared with monotherapy with ceftriaxone, for control of gonorrhea among men who have sex with men in the Netherlands.
Methods: We developed a transmission model and calculated the numbers of new gonorrhea infections, consultations at health care specialists, tests, and antibiotic doses. With these numbers, we calculated costs and quality-adjusted life-years (QALY) with each treatment; and the incremental cost-effectiveness ratio (ICER) of dual therapy compared to monotherapy. The impact of gonorrhea on human immunodeficiency virus transmission was not included in the model.
Results: In the absence of initial resistance, dual therapy can delay the spread of ceftriaxone resistance by at least 15 years, compared to monotherapy. In the beginning, when there is no resistance, dual therapy results in high additional costs, without any QALY gains. When resistance spreads over time, the additional costs of dual therapy decline, the gained QALYs increase, the ICER drops off and, after 50 years, falls below €20,000 per QALY gained. If azithromycin resistance is initially prevalent, resistance to the first-line treatment rises almost equally fast with both treatment strategies and the ICER remains extremely high.
Conclusions: Compared with ceftriaxone monotherapy, dual therapy with ceftriaxone and azithromycin can considerably delay the spread of ceftriaxone resistance, but may only be cost-effective in the long run and in the absence of initial resistance.
A cost-effectiveness analysis found that dual therapy with ceftriaxone and azithromycin can considerably delay the spread of ceftriaxone resistance, compared with ceftriaxone monotherapy, but it may not be cost-effective.
From the *Department of Epidemiology and Surveillance, National Institute for Public Health and the Environment, Bilthoven; †STI Outpatient Clinic, Public Health Service of Amsterdam; ‡Department of Dermatology, Academic Medical Center; §Center for Infection and Immunity Amsterdam, Academic Medical Center; ¶SOA/AIDS Nederland; ∥Department of General Practice Medicine, University of Amsterdam, Amsterdam; #Public Health Service Rotterdam Rijnmond; ††Department of Public Health, Erasmus Medical Center, Rotterdam; ‡‡Department of Medical Statistics and Bioinformatics, Leiden University Medical Centre, Leiden; and §§Julius Center, University Medical Centre, Utrecht, The Netherlands
The authors would like to thank Sanne Hofstraat, Loes Soetens, and Femke Koedijk for assistance with data on gonococcal resistance to antibiotics; Hanneke de Graaf for kindly providing data of Rutgers on the frequency of STI testing; Menne Bartelsman, Karlijn Kampman, and Veerle Wieërs for providing information on the costs of consultations at STI clinics, costs of antibiotics, and costs of pharmacy fees; Martijn van Rooijen and Fleur van Aar for providing data on partner notification. The authors thank the anonymous reviewers for their valuable suggestions and comments that substantially improved the manuscript. Part of this work has been presented at the 29th European Conference on Sexually Transmitted Infections (IUSTI), Sitges, 24–26 September 2015, Poster Number P173.
Conflicts of interest: None declared.
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Correspondence: Maria Xiridou, PhD, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands. E-mail: maria.xiridou@rivm.nl.
Received for publication December 17, 2015, and accepted May 10, 2016.
