Comparison of In-Person Versus Telephone Interviews for Early Syphilis and HIV Partner Services in King County, Washington (2010-2014)

Background: Early syphilis (ES) and HIV partner services (PS) traditionally use in-person interviews. Telephone interviews may be more efficient, but their relative effectiveness is uncertain. Methods: We used multivariable Poisson regression to compare partners named, notified, tested, diagnosed, and treated (ES only) per original patient (OP) who underwent in-person versus telephone PS interview in King County, Washington from 2010-2014. Results: For ES (682 in-person, 646 telephone OP interviews), in-person interviews were associated with more partners named (aRR=1.68[95% CI: 1.55-1.82]), notified (aRR=1.39[1.24-1.56]), tested (aRR=1.34[1.16-1.54]), and empirically treated (aRR=1.19[1.03-1.37]) but no difference in infected partners treated (aRR=0.93[0.72-1.21]). For HIV (358 in-person, 489 telephone OP interviews), in-person interviews were associated with more partners named (aRR=1.38[1.18-1.62]), notified (aRR=1.24[1.03-1.50]), and newly diagnosed with HIV (aRR=2.17[1.04-4.50]) but no difference in partners tested (aRR=1.15[0.88-1.52]). Conclusions: These data support prioritizing in-person HIV PS and suggest that in-person syphilis PS may not have major benefit over telephone PS.