Public opinion about the COVID-19 pandemic in the US is deeply divided by political affiliation,1 including beliefs about the value of ineffective2,3 COVID-19 treatments such as hydroxychloroquine sulfate, an antimalarial drug, and ivermectin, an antiparasitic drug. There is increased prescribing4 of these treatments despite evidence against their effectiveness. We hypothesized that the county-level volume of prescriptions for hydroxychloroquine and ivermectin—but not other, similar medications—would be associated with county-level political voting patterns in the 2020 US presidential election.
In 2019, prescribing of hydroxychloroquine and ivermectin did not differ by county Republican vote share quartile (Figure 2). In early 2020, hydroxychloroquine prescribing volume was differentially lower in the highest Republican vote share counties vs the lowest (−25.1 new prescriptions per 100 000 enrollees in April; P < .001). However, after June 2020, coinciding with the revocation of the US Food and Drug Administration’s emergency use authorization for hydroxychloroquine, prescribing volume was significantly higher in the highest vs lowest Republican vote share counties (+42.4 new prescriptions per 100 000 enrollees, P < .001), 146% higher than 2019 overall baseline prescribing volume (Figure 2).2,5,6
In December 2020, ivermectin prescribing volume was significantly higher in the highest vs lowest Republican vote share counties (+80.9 new prescriptions per 100 000 enrollees, P < .001), 964% higher than 2019 overall baseline prescribing volume (Figure 2). For both methotrexate and albendazole, we found no association between prescribing volume in 2020 and county-level Republican vote share.
In late 2020, the number of new prescriptions for hydroxychloroquine and ivermectin was higher in counties with higher Republican vote share, whereas in early 2020, before revocation of the Food and Drug Administration’s emergency use authorization, prescribing volume for hydroxychloroquine was higher in counties with a lower Republican (ie, higher Democrat) vote share. These findings were absent before the COVID-19 pandemic and for 2 control drugs.
This study has limitations. In an observational study, we could not address the causality of the association between county-level political voting patterns and prescribing of 2 ineffective COVID-19 treatments. Also, we were unable to assess the specific contribution of patient, physician, or other factors to the prescribing patterns.
These limitations notwithstanding, our findings are consistent with the hypothesis that US prescribing of hydroxychloroquine and ivermectin during the COVID-19 pandemic may have been influenced by political affiliation. Because political affiliation should not be a factor in clinical treatment decisions, our findings raise concerns for public trust in a nonpartisan health care system.