Impact of Expedited Partner Therapy (EPT) Implementation on Chlamydia Incidence in the United States

Background: The diagnosis and treatment of C. trachomatis infection is important to preventing persistent or recurrent infection. Expedited partner therapy (EPT) is the favored and supported method for STI treatment when the provider cannot be assured that all recent sexual partner(s) will seek therapy by the Centers for Disease Control and Prevention. EPT is legally permissible in 38 states and is endorsed by healthcare organizations to decrease the rates of chlamydia and gonorrhea infection. Our study investigated the impact of EPT legal status (permissible, potentially allowable, or prohibited) on C. trachomatis infection rates for each state.

Methods: Our ecological study, modeled the number of reported chlamydia cases from 2000-2013 as a function of year, legal status, and the interaction between year and legality. We used a negative binomial regression model that included state fixed effects to account for both the repeated measures per state and state-specific characteristics that could not be measured for inclusion in this study. Each state’s total population for a given year was included in the model as an exposure parameter.  States were designated Y (EPT legal), N (EPT illegal), and M (EPT ambiguous), and the legal status of each state could vary over time.

Results: Each legal category saw an increase in the incidence rate of C. trachomatis infection over time, but on average, the incidence rate for states with prohibitive EPT legislation grew significantly faster over time compared to the rate for the states where EPT was permissible.  

Conclusions: Our model suggests that a lack of or ambiguity in EPT legislation is associated with an increase in STI rates. States with inconsistent EPT legislation as of 2013 (n=8) should consider permitting EPT as a component of a multi-pronged strategy for treatment of sexual partners to prevent C. trachomatis infection.