Doxycycline compared with azithromycin for treating women with genital Chlamydia trachomatis infections: an incremental cost-effectiveness analysis

Ann Intern Med. 1996 Feb 15;124(4):389-99. doi: 10.7326/0003-4819-124-4-199602150-00002.


Objective: To compare the economic consequences of doxycycline therapy with those of azithromycin therapy for women with uncomplicated cervical chlamydial infections.

Design: Decision analysis in which the health outcomes, costs, and cost-effectiveness of two provider-administered treatment strategies for women with uncomplicated cervical chlamydial infections were compared: 1) initial therapy with doxycycline, 100 mg orally twice daily for 7 days (estimated cost, $5.51) and 2) initial therapy with azithromycin, 1 g orally administered as a single dose (estimated cost, $18.75).

Results: Under baseline assumptions, the azithromycin strategy incurred fewer major and minor complications and was less expensive overall than the doxycycline strategy despite a higher initial cost for acquiring antibiotic agents. In univariate sensitivity analyses, the azithromycin strategy prevented more major complications but was more expensive than the doxycycline strategy when doxycycline effectiveness was greater than 0.93. In a multivariate sensitivity analysis combining 11 parameter estimates selected so that the cost-effectiveness of the doxycycline strategy would be maximized relative to that of the azithromycin strategy, the azithromycin strategy resulted in fewer complications but was more costly. The incremental cost-effectiveness was $521 per additional major complication prevented. However, if the difference in the cost of azithromycin and doxycycline decreased to $9.80, the azithromycin strategy was less expensive and more effective, even under these extreme conditions.

Conclusions: On the basis of the best available data as derived from the literature and experts, the azithromycin strategy was more cost-effective than the doxycycline strategy for women with uncomplicated cervical chlamydial infections. Despite the dominance of the azithromycin strategy over the doxycycline strategy, the adoption of the azithromycin strategy may be limited by the practical financial constraints of our currently fragmented health care system, in which the costs and benefits of preventing chlamydia sequelae are often incurred by different components of the system.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Azithromycin / administration & dosage
  • Azithromycin / economics*
  • Chlamydia Infections / drug therapy*
  • Chlamydia Infections / economics
  • Chlamydia trachomatis*
  • Cost-Benefit Analysis
  • Decision Trees
  • Doxycycline / administration & dosage
  • Doxycycline / economics*
  • Drug Administration Schedule
  • Female
  • Genital Diseases, Female / drug therapy*
  • Genital Diseases, Female / economics
  • Health Care Costs
  • Humans
  • Multivariate Analysis
  • Sensitivity and Specificity
  • Treatment Outcome


  • Azithromycin
  • Doxycycline