I continue to lament the difficulty of interpreting the Coronavirus/COVID-19 data pushed at us on a daily basis whether through the media or through government sources of one sort or another. Numbers without context are unhelpful at best, dangerous worst.
Case in point – daily updates on new COVID-19 positive tests in our county.
On nearly a daily basis I receive an e-mail from our city detailing the number of new cases of COVID-19 reported. Presumably through testing. The source of this data is our county public health office, and the news of late has been dire. If you only look at the headline of each e-mail, the very clear and terrible information communicated is that we have 100+ cases of Coronavirus detected in our county on a daily basis.
A compilation of the data communicated just for the last two weeks:
- July 13 – 56 “new confirmed cases of COVID-19” in our county
- July 14 – 184 “new confirmed cases of COVID-19” in our county
- July 15 – 89 “new confirmed cases of COVID-19” in our county
- July 16 – 224 “new confirmed cases of COVID-19” in our county
- July 17 – 137 “new confirmed cases of COVID-19” in our county
- July 20 – 85 “new confirmed cases of COVID-19” in our county
- July 21 – 135 “new confirmed cases of COVID-19” in our county
- July 22 – 160 “new confirmed cases of COVID-19” in our county
- July 23 – 162 “new confirmed cases of COVID-19” in our county
Add these up and one would logically conclude that, as per the e-mail title, there are 1232 new cases of COVID-19 in our county. That’s a big number. Our county population per 2019 census data is 446,499 people. Which means that .00276 percent of our county is infected. That sounds like a much smaller number, but of course small numbers can be very dangerous if we’re dealing with a highly infectious and deadly virus.
I won’t go into a discussion on whether that’s actually the case or not.
And I’ll ignore that the VAST majority of these confirmed new cases occur roughly 65 miles away in the north end of our county. So our city is roughly 65 miles away from the real problem area for our entire county, yet our city is subject to the same restrictions as this infection epicenter. Despite the fact that our city is only 95 miles from the center of Los Angeles, a distance that traverses another entire county. Since the governor’s current lockdown orders are on a county-by-county basis, it means we’re affected by happenings 65 miles away in our own county, where we wouldn’t be affected by happenings just a little farther away in one of the largest metropolitan areas in the United States.
I’ll ignore that for now. Grudgingly.
The e-mail headlines add up to 1232 new cases of COVID-19 in the last two weeks. That sounds like good reason to panic. But then you open up the e-mail.
The first thing we’re then told is that the county is reporting this number of new cases. Reporting is different than being. Reporting is at least one step removed from the actuality of an infection, because reporting may or may not happen in real-time with the infection. Do the reporting numbers only include tests from this particular day? Could tests from previous days be reported now because they’ve only just had time to process the tests or only just now been able to add those numbers into the mix? We aren’t clear here. A certain number are being reported on this day but there’s no indication that means that certain number were discovered on this day. It’s possible that positive test results are being included from tests conducted at some point in the past.
And it immediately becomes clear this must be the case. Because our county’s current total of confirmed cases is 5,444 since the outbreak began in March. But the number of recovered cases is 5,051. Which means that, taking into account the 32 actual deaths in our county attributed to COVID-19, there are only 361 active cases at the moment. And 162 of those active cases are being reported on this day.
What?
If 1232 cases of COVID-19 have been reported in less than the last two weeks, how can there only be 361 active cases at the moment? And if there were 162 new cases reported yesterday, which are part of those 361 active cases, how could it be that on Tuesday there were allegedly 350 active cases?
The only way that’s possible is if the reported numbers are for cases that were tested so far back that the people have already recovered and are no longer considered active. Indeed, we’re told in the e-mail that 93% of those infected have fully recovered.
So while the e-mail claims it is reporting new, confirmed cases of COVID-19, we need to be cautious in distinguishing this from new, active cases of COVID-19, as that clearly can’t be the case. Apparently, from yesterday to today, despite there being 161 new cases reported, there are really only 11 new active cases. And since there are no new fatalities being reported, it means that of the 161 new cases being reported, 150 of those folks have already recovered. They aren’t currently infected.
I’m not a math major by far, but I think my logic and my arithmetic is good so far. Please point out to me if that’s not the case, or if I’m drawing inappropriate or faulty conclusions from the calculations!
Now let’s just focus on the two reports for 7/22 and 7/23.
On 7/22 I was informed by the city, from the county public health office, that:
- There were 160 new cases of COVID-19 being reported for the day
- Two previously reported cases were found to be duplicates and removed from the numbers about to follow
- There were 5282 positive cases of COVID-19 to date in our county
- Of these 5282 positive cases, 4900 have already recovered and are no longer active cases
- There are currently 350 active cases of COVID-19 in our county
- 160 new cases are included in that 350 number of active cases (this would be the logical, simplest way to interpret this information)
- 32 people have died thus far
- 85 people are currently (I believe) hospitalized for COVID-19 related issues
- 29 of those hospitalized people are in ICU
When I go through those numbers, things appear to add up. Total positive cases to date are 5282, which equals the 4900 recovered folks plus the 350 current active cases and the 32 fatalities. Of the 350 people actively infected at the moment 114 of them are currently hospitalized.
On 7/23 I was informed by the city, from the county public health office that:
- There were 162 new cases of COVID-19 being reported for the day
- There were 5444 positive cases of COVID-19 to date in our county (5282 from the previous day’s totals plus the 162 now being reported)
- Of these 5444 positive cases 5051 are fully recovered and not active cases any longer. The previous day there were 4900 recovered cases noted.
- There are 361 currently active cases of COVID-19 in the county. The day before there were 350 active cases. Which means that of the 162 new cases reported today, only 11 are active cases. The other 150 reported cases are earlier cases where the person is already recovered
- There are 86 people now in ICU (up one from the day before)
- There are 27 people hospitalized in total for COVID-19 related issues, down two from the day before
None of this interpretation is provided or highlighted or summarized in the e-mails. I’d like to better understand how it is our whole county is under lockdown and my parishioners are prohibited from gathering to worship when there are, in reality, only 11 new active cases of COVID-19 reported in our county in a 24 hour period.
Pay attention to the details. Don’t assume that what you’re being given means what you think it means. Look through the data with other people and try to make sense of it. You might be surprised at the picture you arrive at compared to the picture painted for you just through headlines or selected numbers.