Routinised Syphilis Screening among Men Living with HIV: A stepped wedge cluster randomised controlled trial.

Abstract

BACKGROUND\nFrequent syphilis screening may increase early detection and decrease transmission. We implemented an opt-out clinic-based intervention pairing syphilis tests with routine HIV viral load testing. The primary objective was to determine the degree to which this intervention increased the detection of early syphilis.\n\n\nMETHODS\nThe Enhanced Syphilis Screening among HIV-positive Men (ESSAHM) Trial was a stepped wedge cluster-randomised controlled trial involving four urban HIV clinics in Ontario, Canada, from 2015 to 2017. Population: HIV-positive adult males. Intervention (I): standing orders for syphilis serological testing with viral loads. Control (C): usual practice. Outcome: early syphilis diagnosis. We obtained test results via linkage with the centralized provincial laboratory and defined cases using a standardized clinical worksheet and medical chart review. We employed a generalized linear mixed model with a logit link to estimate odds ratios (OR) and 95% confidence intervals (CI) of the intervention.\n\n\nFINDINGS\n3,895 men were followed over 7,471 person-years (PY). The mean number of syphilis tests increased from 0.53 to 2.02 tests per person per year. There were 217 new diagnoses of syphilis (C: 81; I: 136), for which 147 (68%) were cases of early syphilis (C:61 (75%); I:86 (63%)). The annualized proportion with newly-detected early syphilis increased from 0.009 to 0.032 with implementation of the intervention; the corresponding time-adjusted OR was 1.25 (CI 0.71, 2.20).\n\n\nINTERPRETATION\nThe implementation of standing orders for syphilis testing with HIV viral loads was feasible and increased testing yet produced less-than-expected increases in case detection compared to past uncontrolled pre-post trials.