Comparison of in-Person Versus Telephone Interviews for Early Syphilis and HIV Partner Services

Background:  Early syphilis (ES) and HIV partner services (PS) have traditionally used in-person interviews.  However, such interviews are resource intensive.  Telephone interviews may be more efficient, but their relative effectiveness is uncertain. 

Methods:  We compared outcomes among original patients (OPs) receiving in-person versus telephone PS for ES and newly diagnosed HIV in King County, Washington from 2010-2014.  We used multivariable Poisson regression to evaluate indices (number of partners per OP interviewed) for partners named, notified, tested, diagnosed and treated (ES only).  Analyses controlled for OP age, gender, race/ethnicity, sexual orientation, time from diagnosis to interview, place of diagnosis and caseworker providing PS.

Results:  For ES, 682 and 646 OPs underwent in-person and telephone interviews, respectively.  For HIV, 358 and 489 OPs underwent in-person and telephone interviews, respectively.  For both, OPs receiving in-person PS were more likely to be younger, diagnosed in STD clinic and interviewed sooner and were less likely to be White (p<=0.001).  For ES, in-person PS was associated with higher indices of partners named (in-person index (IPI)=3.43, telephone index (TI)=2.06, aRR=1.68 [95% CI: 1.55-1.82]), notified (IPI=1.70, TI=1.13, aRR=1.39 [1.24-1.56]), tested (IPI=1.15, TI=0.72, aRR=1.34 [1.16-1.54]) and empirically treated (IPI=1.03, TI=0.74, aRR=1.19 [1.03-1.37]) but no difference in infected partners treated (IPI=0.28, TI=0.24, aRR=0.93 [0.72-1.21]).  For HIV, in-person PS was associated with higher indices of partners named (IPI=1.87, TI=1.28, aRR=1.38 [1.18-1.62]), notified (IPI=1.38, TI=0.92, aRR=1.24 [1.03-1.50]) and newly diagnosed with HIV (IPI=0.10, TI=0.05, aRR=2.17 [1.04-4.50]) though no difference in partners tested (IPI=0.61, TI=0.48, aRR=1.15 [0.88-1.52]).

Conclusions:  In-person syphilis PS interviews were associated with identifying, notifying and empirically treating more partners but there was no increase in infected partners treated.  In contrast, in-person HIV PS interviews resulted in increased HIV case-finding. These data support prioritizing in-person HIV PS and suggest that in-person syphilis PS may not have major benefit over telephone PS.