Question: Have you seen this paper, Associations Between Governor Political Affiliation and COVID-19 Cases, Deaths, and Testing in the U.S.?  How well done is it?

Answer: Thanks for sharing.  I had not seen the paper, which was published just last week in American Journal of Preventive Medicine.  For folks who also haven’t seen the paper, I’ve included a brief synthesis below.  I’m a bit loathe to focus attention on the role of political affiliation in COVID-related policies, attitudes, and behaviors for concern that it will further drive partisan wedges.  That said, ignoring the issue won’t make it go away; we have a growing evidence base that political affiliation is a key factor for individual, community, and state-level public health attitudes, behaviors, and policies (a few examples are here, here, here, and here).  This paper adds to that evidence base and is quite rigorous in its approach, particularly because it controls for a number of potentially confounding variables (like age, rurality, population density).  But like all studies, this one has its limitations.  For example, while the authors tried to adjust for the pandemic’s progression across the country– from early waves in New York and Washington (“blue” states) to later waves in more rural and inland states (“red” states)– there is likely residual confounding.  Additionally, I would have liked to have seen more data and discussion about outlier states– ones that were either especially stringent or lax in their approach to COVID– including the degree to which potential outliers may be driving the political affiliation differences we’re seeing.  Finally, this is a study looking at association, not causation.  It’s difficult to disentangle how much the policy approach drives individual response and how much individual response drives the policy response.  

Paper Synthesis: This study used data from covidtracking.com to explore time trends (mid-March through mid-December) in COVID-19 testing, cases, and deaths by state in the US.  The main question of interest is whether gubernatorial political party affiliation was associated with better/worse outcomes after adjusting for a host of factors– state population density, rurality, Census region, age, race, ethnicity, poverty, number of physicians, obesity, cardiovascular disease, asthma, smoking, and presidential voting in 2020.  Authors find that there is a modest statistically significant difference in testing, case load, and deaths per population associated with each state governor’s political affiliation.  “From March to early June, Republican-led states had lower COVID-19 incidence rates compared with Democratic-led states. On June 3, the association reversed, and Republican-led states had higher incidence (RR=1.10, 95% PI=1.01, 1.18). This trend persisted through early December. For death rates, Republican-led states had lower rates early in the pandemic, but higher rates from July 4 (RR=1.18, 95% PI=1.02, 1.31) through mid-December. Republican-led states had higher test positivity rates starting on May 30 (RR=1.70, 95% PI=1.66, 1.73) and lower testing rates by September 30 (RR=0.95, 95% PI=0.90, 0.98).”