Comparison of partner notification at anonymous and confidential HIV test sites in Colorado.

We compared health department-initiated partner notification at a single anonymous human immunodeficiency virus (HIV) test site in Denver to 13 confidential HIV test sites throughout Colorado over an 18-month period. The average number of named, notified, and counseled in-state partners was from 30 to 50% greater among confidential site index cases than anonymous site index cases, and the seropositivity rate in newly tested partners of confidential site index cases was more than twice the rate in partners of anonymous test site index cases. When analyses were restricted to gay/bisexual male index cases, the results were the same as for the total group. We recommend that state and local health departments collect data to evaluate and improve the delivery of partner notification services.