Kansas COVID-19 Update, Week 4

 

Last week's update was a good reminder for me to watch out for outliers in the data and be skeptical of large swings. The positivity rate in Kansas has been trending up, but if it had jumped to 18.6% that would have been truly remarkable — in a bad way. Thankfully it had not. But it's still too high. We'll check in on that number again this week, and also break down a mask mandate graphing controversy.

The Good: There was a significant improvement in the reproduction rate (Rt) in Kansas this week, as it dropped from 1.07 to 1.04. This is great news! If we can get that figure below 1.0, the number of active COVID-19 cases will begin to decrease. Getting Rt below 1.0 and keeping it there is the key to stabilizing the pandemic until we have a vaccine or effective treatment. The latest drop in Rt means we're doing a better job of keeping our germs to ourselves by doing things like wearing masks and maintaining a safe distance from each other, especially indoors. As noted in previous weeks, Rt is very hard to pin down. While one group of data analysts has now pegged it at 1.04 in Kansas, another group still has us at 1.1 (and both groups say it could potential range anywhere from 0.77 to 1.20). More testing would help us get a more accurate number.

The Neutral: Hospital capacity is holding steady for the second week in a row, with 113 Kansas hospitals reporting about 38% of their ICU beds available. That's actually a slight improvement from last week, and we're still well within a range where we should be able to give each patient the best care possible. 

The Bad: No "ugly" news this week, but the test positivity rate still doesn't qualify as "good" or even "neutral." According to Johns Hopkins, 11.8% of COVID-19 tests in Kansas came back positive last week. Two weeks ago that figure was 11.0% and the week before that it was 10.7%. The trajectory is not good. Again, more testing would improve this measure.

Bonus: During a news conference this week, KDHE Sec. Lee Norman said the rate of new COVID-19 infections is decreasing in the 15 Kansas counties with mask mandates and is not decreasing in the 90 counties without mandates. Then he showed this graph:

It's a bad graph. You shouldn't combine two different Y-axes, especially with different scales, on the same chart. At a glance, it looks like the mask mandate counties now have lower COVID-19 rates than the non-mask counties. Only if you really look closely can you tell that's not the case. 

 

Michael Austin, an economist formerly with the Brownback Administration who opposes mask mandates, re-created the graph with a single, standard Y-axis.

If someone manipulated and presented data in the private sector to the upper management, they’d be fired for misleading their employer. #ksleg #ksecon #COVID19 @SecNorman works for Kansans, and he was trying to mislead us, plain and simple. #MaskMandate pic.twitter.com/oGZk3tgAaM

— Michael Austin (@KSTaxEconomist) August 7, 2020

That second graph shows quite clearly that non-mask counties have a lower COVID-19 rate than mask counties. But it still shows that counties that enacted mask mandates have since seen their daily cases go down (by about 40%), while counties that didn't enact mandates have had their case rates remain relatively flat. In other words, while Austin's graph is an effective argument against KDHE's chart, it's not really an effective argument against masks. In fact, it's evidence that mask mandates work, unless there's some other variable that explains that difference.

It's also important to remember that Kansas is just one small state in a global pandemic, and there is a lot more data out there. This study published in Health Affairs (a peer-reviewed health policy journal), found a similar phenomenon throughout the U.S.: states that enacted mask mandates "had a greater decline in daily COVID-19 growth rates after issuing these mandates compared with states that did not issue mandates." The University of Kansas Medical Center's COVID-19 Daily Digest (which I highly recommend, even though it's not actually updated daily), includes an entire section on masks, with links to several more studies. The data from these studies is quite clear: masks are a good way to reduce the spread of the novel coronavirus, even among people who live in the same house.

The question of whether you HAVE TO wear a mask in indoor public places depends on who is in office where you live, so it is a political question, by nature. But the question of whether you SHOULD wear a mask is not actually political at all. It's a question about your health, as well as the health of your family, your community and your state.