January Winner Declared: Colorado Kid Corona Case Mask Comparison

Unmasked Douglas County crosses the Omicron finish line in first/best/lowest cases place to date

Remember that Colorado is running a natural experiment where Douglas County school district has unmasked their kids in late Nov/ early Dec 21 while Cherry Creek and Littleton have not, but all three still remain under the same “Tri-County” health department reporting scheme.

With Omicron (maybe) subsiding we now have cases at their lowest level since early fall (or possibly ever if the retrospective data was available to check) and surprisingly low in all three districts. HOWEVER: Looking at the latest data table there have been a number retroactive adjustments (which I have updated) suggesting that there is a month plus data adjustment lag similar to what we normally see in excess deaths data which has an influence on the current droop. Interesting but not wildly surprising.

The cumulative chart gives the tail of the tape and shows Douglas crossing the finish line decisively in first place (lowest cumulative cases) in elementary ages and winning in a photo finish for high schoolers vs Littleton with Cherry Creek marginally out.

Honestly, there looks to possibly be a signal with younger ages and the “snot nose theorem” that they will run higher on cases, but the likely error bars on this experiment probably preclude decisive judgements even as good as the A/B comparison setup is.

Bottom line remains that there is there remains no obvious signal here for mask efficacy. I’ll keep watching but I’m not holding my breath.

Here is the data pixel scrape for the record: