Provider Implicit Bias in Prescribing HIV Pre-exposure Prophylaxis (PrEP) to People Who Inject Drugs

Multiple HIV outbreaks among people who inject drugs (PWIDs) have occurred in the USA since 2015, highlighting the need for additional HIV prevention tools. Despite high levels of need, pre-exposure prophylaxis (PrEP) is drastically underutilized among PWIDs. Implicit bias toward PWID held by clinicians may impede PrEP scale-up among these underserved patients. This study examined how primary care providers' (PCPs) clinical decisions related to PrEP can be impacted by biases when the patient has a history of substance use.

We conducted an online survey of PCPs (n = 208). The survey included the implicit association test (IAT) to assess unconscious attitudes toward PWIDs, direct questions regarding clinicians' explicit PWID attitudes, and an embedded experiment in which we systematically varied the risk behavior of a hypothetical patient and asked PCPs to make clinical judgments.

A minority (32%) of PCPs reported explicit PWID bias. The IAT indicated strong implicit PWID bias (meant IAT score = 0.59, p < .0001) among 88% of the sample. Only 9% of PCPs had no implicit or explicit PWID bias. PWID patients were judged as less likely to adhere to a PrEP regimen, less responsible, and less HIV safety conscious than heterosexual or gay male patients. Anticipated lack of adherence mediated PCPs' intent to prescribe PrEP to PWID.

PCPs' bias may contribute to PrEP being under-prescribed to PWID. Implicit and explicit PWID biases were common in our sample. This study illustrates the need to develop and test tailored interventions to decrease biases against PWID in primary care settings.