A fresh look at COVID-19 data
By: Devin Kennemore
Mr. Kennemore is a professional Environmental Scientist and consultant with just under 30 years of experience who has lived New Mexico for 20 years. He holds BS and MS degrees in biology from the University of South Carolina.
The data presented is taken from The COVID Tracking Project https://covidtracking.com, sponsored by The Atlantic. The historical data for New Mexico is found at https://covidtracking.com/data/state/new-mexico#historical.
The data we have been looking at in the news are presented in a less-than-optimal way to understand the undistorted facts. While the numbers for New Tests are given as a daily total, the numbers for Cases, Hospitalized, and Deaths are provided as cumulative totals going all the way back to the beginning of the data set. Cumulative totals are deceptive in that they are much larger than daily totals and they don’t tell the real story. In order to find the real story, you have to subtract the previous day’s total from the current day’s total to get the current daily total. By doing this the results are more revealing.
These results are presented in three spreadsheets. The first spreadsheet tracks the daily deaths from COVID-19. These numbers are among the most important, because most people agree that death is the worst and most feared potential result of contracting the virus.
The second spreadsheet tracks daily new cases of COVID-19. The key metric in this data set is not so much the number of cases, but the daily number of new cases per daily number of new tests. This value is expressed as a percentage since there are far fewer cases than tests. This value is so important because it removes the effect of variability in the daily new test numbers. What we really want to know is not how many new cases there are, but are more people really becoming infected?
The third spreadsheet combines the data for daily new cases, new deaths, and new hospitalizations, so that we can see how they compare.
What the Data Actually Tell Us
The daily number of deaths from COVID-19 peaked around mid-May with an average daily value of approximately 8 deaths statewide per day. Daily deaths continued to decline after this until early July when the average daily value bottomed out at approximately 3 deaths statewide per day. The daily average rose back up to 5 by the end of July and lately has been trending back down. New Mexico is currently averaging approximately 4 deaths statewide per day. The overall average daily number of deaths since the first case was recorded in New Mexico is approximately 4.5. According to the U.S. Census Bureau, the most recent estimated population of New Mexico (for 2019) was 2,096,829, or roughly 2.1 million.
As of August 10, 2020, the total number of deaths from COVID-19 in New Mexico was 683. Given a population 2.1 million people, that means that we have experienced approximately 32.5 deaths per 100,000 residents for the entirety of the pandemic. By comparison, during the 2018-2019 influenza season (Oct.-May), New Mexico experienced 11 deaths from pneumonia and influenza per 100,000 residents and in the prior season, 14 deaths per 100,000 residents (New Mexico Epidemiology, Vol. 2019, No. 10). So far, that means in New Mexico, the chances of a random resident dying of COVID-19 are roughly two and one-half to three times their chances of dying from pneumonia or influenza in recent years. Not to diminish the value of every human life, but these are not large numbers. On any given day, a random New Mexico resident has approximately 2.1 chances in a million to die from COVID-19. Those are pretty good odds.
Daily new deaths from COVID-19
The dotted trendline approximates the running average and notice that generally speaking, the line is relatively flat and there is no spike in deaths corresponding to the “spike” in cases. A very slight uptick, yes, but nothing anyone could realistically call a spike.
Daily new cases
From the beginning of tracking in early March, there was a daily rise in new cases, which leveled off in early May at around an average of 140 new cases per day. It declined slightly until the beginning of June, settling at around an average of 130 new cases per day. In early June, there was another significant rise in daily new cases, peaking most recently in late July at around an average of 300 new cases per day. For the most recent two weeks, daily new cases have been trending downward with the most recent 3-day average as of August 11 being around 160 new cases per day.
At first glance, these numbers would seem to support the claim that New Mexico experienced a “second wave” of infections from COVID-19, which is now passed (see the graph below); however, a closer look at the data reveals the truth.
As testing began, our testing capacity was extremely limited. As time progressed, our testing capacity increased; however, in order to make sure we had enough tests to go around, we limited testing to those who were experiencing actual symptoms of COVID-19. That made sense. If you’re not sick, you’re not in immediate danger of death from COVID-19.
In late April, our testing capacity increased dramatically and we opened up testing to anyone who wanted to be tested. A “case” was redefined in the process from being someone who exhibited symptoms and tested positive for COVID-19 to anyone who tested positive for COVID-19, even if they were entirely asymptomatic. To find out the impact of increased testing and the new definition of a “case,” the effects of these variables from the data must be removed. To do so, simply divide the number of daily new cases by the number of daily new tests performed. The result is startling.
As shown quite clearly in the graph above and the graph below, the daily number of new cases correlates very closely to the number of daily new tests performed since the beginning, with very minor small-scale variations.
The next thing to notice is the difference in the scales of the two graphs. The scale for New Tests is approximately 23 times as high as the scale for New Cases! To see what that means visually, the next graph, below, shows the two data sets on the same scale. It is difficult to see a spike in new cases in this graph.
And now, the most important graph of all, the graph that tells the real story, is the graph showing the weekly average number of new cases per test, below.
The peaks on this graph are artifacts of the data set that resulted mostly in the beginning of the pandemic when data collection was still being organized and the initial challenges that go along with any major data collection effort is undertaken. Over time, as the data collection process became more streamlined, the line becomes more stable. The trendline, shown as a dotted line, provides a more accurate picture of reality. And the reality is, since the beginning of June, when the “spike” in new cases began, the weekly average number of cases per test has not exceeded 5 percent and for the last 4 weeks this average has been in decline. For the most recent week recorded, that average number of cases per test was 2.9 percent.
The bottom line is, the “spike” in cases was caused by the spike in new testing and the testing of people who were and are asymptomatic. The reality is, fewer and fewer residents of New Mexico are coming down with COVID-19 and at some point no amount of testing will give the appearance otherwise.
This also means that there isn’t going to be a third wave, because there never really was a second wave. If you start hearing about a third wave, follow the data. Therein lies the truth.
The next data set to look at: Hospitalizations.
Hospitalizations, new cases and deaths
The third spreadsheet includes daily new hospitalizations from COVID-19 along with daily new cases and daily new deaths. A graph of these data is shown here:
This graph clearly shows that the number of daily new hospitalizations and deaths did not dramatically increase with the number of new cases. This is further evidence that the “spike” in new cases was caused entirely by the extreme increase in new testing.
So, what does all this mean? The number one justification for all the public health orders mandating the closure of “non-essential” businesses, social distancing, mask wearing, self-quarantine, and staying at home except for emergencies and absolute necessities, was the oft repeated mantra of a spike in cases, the ever growing number of deaths and hospitalizations, and the rationalization that if these measures “save just one life” they will have been worth it. The questions before us are - Is it worth it? Has it been worth it? That is left for you to decide for yourself, because as New Mexicans, that’s what we do.