U.S. states led by Republican governors had much higher rates of COVID-19 infections and deaths throughout 2020, according to a new analysis that quantifies how much politics impacted the effects of the pandemic.
The sweeping longitudinal analysis, published March 9 in the American Journal of Preventive Medicine, gathered data from all 50 states and Washington, D.C., on COVID-19 daily incident cases, test-taking rates, test positivity rates and death rates between March 15 and Dec. 15.
"Last year, the pandemic became very politically polarized," Brian Neelon, the lead author of the study and professor at the Medical University of South Carolina, told The Academic Times. "We hypothesized, based on our data, that this had an impact on the policy decisions of states and subsequently on how they handled the virus and ultimately on [COVID-19] cases, death rates and so on."
Though this analysis is being published a year into the pandemic, and at a time when the U.S. is nearing mass implementation of the COVID-19 vaccine, Neelon indicated that the findings continue to remain relevant and salient.
Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, "warned not to loosen public restrictions too much and too early," Neelon said. "And despite this warning, many states have started to lift mask mandates, for example. So our findings are still relevant because they suggest that policy decisions have health consequences and they should be guided by public health recommendations rather than political beliefs."
The data sample they used came from two publicly available sources: COVID-19 daily incident cases and death rates came from the COVID Tracking Project, headed by the Atlantic Monthly Group; and COVID-19 testing and test positivity rates came from a database collected by the Department of Health and Human Services.
The study used a Bayesian negative binomial model to analyze the data, which is a type of regression model in statistics.
"In our case, the response variables were COVID-19 cases, deaths and tests, and the predictor variables are state governor political affiliation," Neelon said.
In order to isolate this association, the study adjusted for confounding factors, including state population density, rurality, poverty, age, race, ethnicity, number of physicians and any known underlying health conditions.
The study found that, while Democratic-led states had higher per capita rates of COVID-19 cases, positivity tests and deaths early in the pandemic, these trends started to reverse in late spring.
For example, on April 15 — about a month into the pandemic — Democratic-led New York reported a total of 1,105 COVID-19 cases per 100,000 residents, while Republican-led Florida reported a total of 95 cases per 100,000. Likewise, Democratic-led California reported 62 cases per 100,000, while Republican-led Texas reported 52 cases per 100,000.
The study posits that these early trends could be explained by the fact that states led by Democratic governors were home to initial ports of entry for the virus in early 2020. Once May arrived, however, these trends started to reverse.
On May 30, Republican-led states began to have higher test positivity rates, which Neelon said could occur, "if either the number of positive tests is large or if very few tests are performed." Then, on June 3, COVID-19 incidence rates were higher among Republican-led states.
Neelon noted, though, that both these measures use "confirmed," or reported, cases because, "Unfortunately, it's hard to obtain accurate data on those who are asymptomatic and hence do not show up for testing; thus, in general, underreporting of cases is a problem, although more sophisticated epidemiologic models attempt to account for this."
Republican-led states began to see higher rates of COVID-19 deaths on July 4, according to the analysis, with an estimated 1.56 deaths per million on average among states with Republican governors, compared to 1.33 deaths per million on average among states with Democratic governors.
This means that the fatality rate was approximately 1.17 times higher on average in states with Republican governors than in states with Democratic governors, a difference that widened within one month.
On Aug. 5, the average death rate among states with Republican governors was estimated to be 3.09 deaths per million, versus 1.72 deaths per million among states with Democratic governors.
"Thus, on that date, death rates were about 1.8 times higher in states with Republican governors compared to states with Democratic governors," Neelon said.
These trends continued through the rest of the year as the pandemic unfolded — all the way up to the end of the study period in mid-December.
Neelon explained, though, that, "These values are estimates obtained from our model after controlling for factors such as state poverty level, population density, etc."
Testing rates were the only metric that stayed approximately the same between Republican-led and Democratic-led states from mid-March to mid-September. It was not until the end of September that this changed, a finding that initially surprised the researchers.
"Around September 30, states with Democratic governors started testing at a higher rate than Republican governors," Neelon told The Academic Times. "That itself isn't surprising, but we hypothesized that we would see this difference much earlier in the year. We think that Democratic governors were more aggressive with their testing — say during the summer — but we didn't see that difference until the end of September."
Based on these findings, the study confirms that, "Gubernatorial party affiliation may drive policy decisions that impact COVID-19 infection and deaths across the U.S."
"Our findings suggest that governor party affiliation may have contributed to a range of policy decisions like stay-at-home orders and mask mandates that collectively impacted the spread of the virus," Neelon said, adding that, "Health policy decisions like issuing mask mandates have downstream effects on increasing the number of cases or mitigating cases or deaths depending on the policy."
This analysis also draws on recent studies that examined the differences in health policies issued by Republican and Democratic governors throughout the pandemic.
"Our theory is supported by recent studies that found that Republican governors were less likely to implement stay-at-home orders, and if they did, those stay-at-home orders tended to be of shorter duration," Neelon said. Moreover, the researchers point to another study that identified Democratic political party affiliation of a governor as the most important predictor of state mandates to wear face masks.
"The take-home message is that policy decisions have health consequences and these should be guided by public health recommendations, not political beliefs," Neelon said.
The study "Associations Between Governor Political Affiliation and COVID-19 Cases, Deaths, and Testing in the U.S.," published March 9 in the American Journal of Preventive Medicine, was co-authored by Brian Neelon, Fedelis Mutiso and John L. Pearce, Medical University of South Carolina; and Noel T. Mueller and Sara E. Benjamin-Neelon, Johns Hopkins Bloomberg School of Public Health.