10 States: Population and Testing Data

Today's entry includes more graphs and charts than normal. Most will be updates of graphs previously shared in this blog, some will be new.
The purpose of this blog is to look beyond the state and national totals and compare the trends across states. Ten states are currently included in this data. For added context, at the time of publication, the global total was over 1,428,000 and the US total exceeds 398,000.

As always, Figure 1 depicts the increase in cases over time in ten states. It is difficult to ignore Florida in this image; it is the only state without a smooth curve. I mentioned previously that Florida is the only state with multiple points during the day that data is released. We can speculate that the data reporting intervals could have something to do with the erratic line. The bend in the curve is evident in Colorado, which dipped under Indiana today for the first time in total number of cases. Arizona and Maryland also have visible changes in the slope.

Figure 1. Total COVID Cases over Time in Ten States

Figure 2. Total COVID Cases over Time after 40 Cases Reported

Figure 2 represents the total cases over time after the 40th reported case. This allows or a more direct comparison. Pennsylvania and Florida remain nearly identical. When looking at Figure 2, it is helpful to remember that the four states with the greatest number of cases are also the four states with the greatest population (see Table 1). As reported previously and still true today, Maryland has the highest population density and number of cases per square mile. Michigan remains the highest state of the ten in percentage of the population testing positive. It is worth note, Pennsylvania is creeping up, currently second in both categories.

Table 1. Population, Square Miles, Population Density, and COVID in Ten States

The next figure included here is new. Figure 3 is a visualization of the good news reported in yesterday's post. The daily percentage increases in every state are decreasing. In other words, even though the numbers continue to rise, the speed (or slope of the curve) of the spread is slowing. Each column here represents the percentage increase in the number of cases compared to the previous day, in that state. The downward trend of all the columns is evident when looking left to right.

Figure 3. Daily Percentage Increase of COVID Cases in Ten States

Figures 4 and 5 represent an update to the testing data. Figure 4 depicts the total number of tests each state has reported as of today. Wide scale testing is one thing the public health experts would like to achieve in combating this virus. It is important to look at the total testing numbers in context of the state's population (see Table 1). For instance, California has the greatest number of tests, which represents 0.4% of the population. Indiana (0.43%), Iowa (0.4%), Michigan (0.44%), Colorado (0.49%), and Arizona (0.46%) have all tested a similar proportion of the population. Maryland (0.52%), Missouri (0.55%), Florida (0.65%), and Pennsylvania (0.71%) are over one half of a percent of the population (which, let's be honest, is not great). Of those tests, the percentage positive is also important (see Figure 5).

Figure 4. Total Number Tested for COVID in Ten States

Figure 5. Percentage of Positive COVID Cases in Ten States

Figure 5 shows that Michigan's percentage of positive cases remains drastically higher that the other nine states. As time goes on and more testing is implemented, this number should decrease in every state. The fact that these numbers remain high suggests that the country is not yet testing at the level recommended.

The final piece of data for tonight is relates to the reported race and ethnicity of cases. In my "real research" I examine racial trends in education. Of all this data, this is the closest thing to my expertise. A few days ago I mentioned the data was not good around race and ethnicity, and I mentioned that the number of "unknown" race/ethnicity was too high to really examine the data. That remains my stance today. However, I decided to present the data since the topic is beginning to be broached in the media. The first thing to point out is that only two states have this data publicly available. Second, the number of "unknown" race remains very large, especially in Florida. The Michigan unknown numbers have decreased in recent days.

The columns titled "census" for each state are the percentages of the population which make up each race/ethnicity. The COVID columns are the reported positive in each state by race/ethnicity. When I look at this data I see two things. First, the percentage of White positives in both states is disproportionately low, compared to the total population. Even if every unknown was White, the percentage would not be close to the percentage of White people in Michigan. Second, the Black/African American numbers are disproportionately high in Michigan. This most likely represents the population of Detroit and other cities in Michigan. One thing is clear, the disproportionality in the data will lead to other states reporting this data as well.

Table 2. Race and Ethnicity Data and COVID in Two States

Finally, the mortality rate across all states appears to be consistent [range 1.75% - 4.45%]. Missouri  has the lowest rate, with Pennsylvania, Maryland, Iowa, California, Arizona, and Florida under 3%.  Indiana (3.14%), Colorado (3.3%) and Michigan (4.45%) have the highest mortality rates.

It is projected that the mortality rate will spike after the spike in the number of cases. In other words, we can expect these percentages to increase in the next few weeks. As always, Stay Home, Stay Safe, Stay Healthy -JRB