964 - Opt-Out HIV- Hepatitis C (HCV) Testing at a Primary Care Resident Clinic in Columbia, SC: Who Gets Tested and Who Opts Out of Testing?

Background: South Carolina (SC) remains one of the most heavily affected states for both HIV and HCV infections. Males account for the majority of cases. Implementation of universal opt-out testing has improved screening rates but not much has been published describing the characteristics of those who opt out of testing. This becomes important as 10-50% of patients have opted out in previous studies.

Methods: Between February and August 2019, we conducted a quality improvement (QI) project which implemented opt- out HIV-HCV testing at a single primary care resident clinic in SC with the primary aim of increasing screening rates for HIV-HCV by 50%. Secondary aims included describing the demographic characteristics of the opt-out population. Persons were considered eligible for testing if they were between the ages of 18-65 years for HIV and 18-74 years for HCV. This was prior to the USPSTF 2020 guidelines which recommend HCV screening for adults aged 18-79 years. A retrospective chart review was used to obtain screening rates, opt status and demographic data. Logistic regression and the firth model were used to determine linkages between categorical variables. We present 3-month data.

Results: 1253 patients were seen between May 1, 2019- July 31, 2019 (See Table 1).  985 (78%) were eligible for HIV testing. 482 (49%) were tested for HIV as a result of our QI project and all tests were negative. 212 (22%) of eligible patients opted out of HIV testing. Males were 1.59 times more likely to opt out (p=0.008). ( see Table 2,3)
Regarding HCV, 1136 (90.7%) were deemed eligible for testing. 503 (44%) were tested for HCV as a result of our QI project.  12 (2.4%) were HCV antibody positive with viremia. 11 (90%) of antibody positive with viremia cases were in the 1945-1965 birth cohort (see Table 4). 244 (21%) opted out of HCV testing. Males and persons without a genitourinary chief complaint were more likely to opt out (p=0.02).Table 1: Demographic characteristics of the population seen at the internal medicine resident clinic between May- July 2019
Table 2: Relationship between demographic variables and the odds of being tested for HIV or HCV within the last 12 months. Logistic Model.
Table 3: Relationship between demographic variables and the odds of opting out of testing for HIV or HCV. Firth Model.


Conclusion: Although implementation of routine HIV-HCV opt-out testing led to increased screening rates for both HIV and HCV, roughly 1 in 5 eligible patients chose to opt out of testing. Males were more likely to opt out despite accounting for the majority of newly diagnosed HCV cases. Future studies investigating drivers for opting-out in the male population could improve testing and assist with early diagnosis.Table 4: Characteristics of patients newly diagnosed with HCV positive with viremia.