Disparities in HIV Prescribing Narrowed As Federal Guidelines Changed, Study Finds

Integrase strand transfer inhibitors (INSTIs) were a major advance in the treatment of HIV. By blocking integrase enzymes, this class of drugs thwarts HIV replication — and in combination with other drugs, that leads to faster, more reliable viral suppression, fewer adverse events and other positive outcomes. The first INSTI approved by the FDA was Isentress (raltegravir) in 2007. Other approvals followed and the INSTIs on the market now include Tivicay (dolutegravir) and Apretude (cabotegravir).

Researchers have found differences in how soon and how often different groups get prescribed INSTIs. Lauren C. Zalla, Ph.D., of the Johns Hopkins’ Bloomberg School of Public Health, and her colleagues reported the results of a study today in JAMA that analyzed racial and ethnic differences in INSTI prescribing as part of the initial antiretroviral treatment of HIV.

In broad strokes, they found that Black and Hispanic patients were less likely to be prescribed INSTIs before the drugs were included in federal treatment guidelines but the disparities narrowed and then disappeared starting in 2014 after the integrase drugs were included in the guidelines.

They also noted that the disparities were larger among those with private insurance or who were uninsured than the disparities among those covered by public insurance (Medicare and Medicaid).

The study was not designed to identify reasons for disparities, but the researchers speculated that the disparities among those with private insurance coverage may reflect differences in overcoming hurdles to access, such as prior authorization.

Lauren Zalla and her colleagues examined disparities in the prescribing of integrase strand transfer inhibitors.

“Because White patients tend to have more money, time and social capital than Black or Hispanic patients, they may have been better equipped to overcome administrative barriers to INSTI prescription, such as preauthorization that was in place before INSTI-containing ART was the standard of care,” Zalla and her colleagues said in the discussion section of their paper.

The researchers used data from the North American AIDS Cohort Collaboration on Research and Design to conduct this study. Their analysis included just over 41,000 patients at more than 200 clinical sites. Slightly less than half (47%) of the patients identified as Black, 16% identified as Hispanic and 33% identified as White. The researchers noted that one limitation of their study is that the subjects were people who had “successfully linked to” HIV care. Prescribing disparities might be identified or large if all the people with HIV in the U.S. were included, not just those who were receiving care and therefore had received a prescription.

In one version of their analysis, Zalla and her colleagues divided INSTI prescribing into four periods.

From Oct. 12, 2007, through July 7, 2009, when INSTIs were only approved by the FDA as salvage therapy, only a small percentage of patients were prescribed INSTIs and the prescribing pattern favored White patients. Five percent of White patients received prescriptions compared with 3.5% of Black patients and 3.1% of Hispanic patients

From July 8, 2009, to April 30, 2014, when integrase drugs were approved by the FDA as initial therapy but not yet included in federal government treatment guidelines, 22.1% of White patients were prescribed INSTIs compared with 3.5% of Black patients and 17.3% of Hispanic patients.

The third period in the analysis went from May 1, 2014, to Oct. 16, 2017. During that time, the recommendation from a federal government panel — the Department of Health and Human Services (HHS) Panel on Antiretroviral Guidelines for Adults and Adolescents — was that INSTIs should be included as an option in the initial therapy for HIV. The researchers found no difference between the likelihood of Hispanic and White patients being prescribed antiretroviral therapy that included an INSTI (71.8% for Hispanic patients vs. 72.4% for White patients) during that time. However, prescribing for Black patient was lower (66.1%).

In October 2017, the HHS panel guidelines changed to make therapy that contained INSTI the single preferred option. In 2018 and in 2019, Zalla and her colleagues found that the likelihood of Hispanic and Black patients being prescribed therapy that included an INSTI exceeded the likelihood of White patients being prescribed INSTI-containing antiretroviral therapy, although the differences did not meet the statistical tests for significance. In 2018, the researchers found that 93.2% of Hispanic patients and 89.9% of Black patients were prescribed INSTIs compared with 90.8% of White patients.

The disparities among people with private health insurance was largest in 2014-2016, according to the researchers. In 2014, the initial antiretroviral therapy of 68.9% of privately insured White patients included INSTI medication compared with 49.2% of privately insured Black patients and 51.7% of Hispanic patients.