Examining COVID19 Positivity-Ratio Trends in US States from April-July: Are Rising Caseloads Attributable to <More Testing> and Do State Political-Affiliations Play a Role?

ImportanceRising Covid19 cases in the US are attributed by some political leaders to more testing. Positivity-ratios (cases to tests ratio) in conjunction with cases and tests provide a better overview. However, comprehensive overviews of positivity-ratio patterns are scarce. ObjectiveTo examine trends in positivity-ratios, tests and cases by state from mid-April-mid-July. Further, to examine whether positivity-ratio patters are associated with state political-affiliations. MethodsState-level publicly available data on Covid19 is used. Seven-day moving averages (MA7) of positivity-ratio are computed for April 21-July 15. States are assigned to four groups based on patterns of change in positivity-ratio - higher at end of study period than beginning (Group 1), initial decline but subsequent increase starting Memorial Day weekend (Group 2), initial decrease but an upturn in last 14 days (Group 3), and consistent downward trend (Group 4). Political-affiliation is categorized as Republican-leaning if President Trump won the state and the governor is Republican. Additionally, a proxy measure is used to indicate intensity of Black Lives Matter (BLM) protests in the state. Associations are tested using chi-square analysis. ResultsFourteen states are in Group 1, fifteen states in Group 2, fifteen states in Group 3, and six states and DC in Group 4. 78.57% of Group 1, 33.33% of Group 2, 40% of group 3, and none in Group 4 were Republican-leaning. The difference in distribution was statistically significant (p<0.01). Distribution of high intensity BLM protests across the four groups was not statistically different (p>0.10). ConclusionIncreased Covid19 cases cannot be attributed to more testing. Indeed, the high positivity-ratios in most states indicate current testing is failing to capture actual infection rates. The association between state political-affiliation and positivity-ratios suggests Republican voters may be somewhat more skeptical of the gravity of the disease and emphasizes the importance of messaging by political leaders.