(UPDATED, APRIL 16)
The latest “metrics” from the Governor’s office once again raise serious questions. A few days ago it seemed clear that two or three of the state’s six regions would very soon reach the magic number 10, at which point shelter-in-place is considered justified by the Governor and the Iowa Department of Public Health, according to their guidelines. Instead, as of April 15, regions 1 and 6 remained stuck at 8 and 9, respectively, and region 5 had fallen to 8. Why? Because the hospitalization rate score, which by deduction must have been at 3 for all 6 regions just a week ago, was suddenly downgraded to 1 in two regions, and 2 in two others.
Today, April 16, things changed again. Lo and behold, Region 6 made it to 10. And in fact the Governor followed through with something akin to shelter in place, with most kinds of gatherings limited to families, not groups of 10 or fewer. No additional business closures were announced, however. Meanwhile, Region 5 jumped two points with new outbreaks at two more nursing homes, but then lost a point because the hospitalization score apparently was lowered again, without any explanation. So it remains at 9, even though it is maxed out on all criteria except hospitalizations.
No explanation of the hospitalization score has been forthcoming beyond the vague definition in the “Guidance” memo unearthed by Zachary Smith of the Iowa City Press-Citizen last week. That memo defines it thus: “Percent of identified cases requiring hospitalization.” Is the numerator the cumulative total of all cases in Iowa that required hospitalization at some point, or just cases in the last 14 days, or just current hospitalizations as of the most recent day? Is the numerator cumulative cases, cases in the last 14 days, or something else? We don’t know, and no hospitalization rate by this measure has been reported even statewide, nor does the newly launched dashboard contain any hospitalization data at the county or regional level.
Total cases of COVID-19 continue to rise, as do current hospitalizations. So in the face of a rising number of Iowans currently with a severe enough case of the virus to be hospitalized, why does the hospitalization score decline, lessening the supposed need for shelter in place? Why is the percent relevant in the first place? Surely the total number of persons hospitalized for the virus is the single most important indicator, since it signifies not only the number of Iowans seriously affected by the virus, but the potential strain on hospital resources.
A forecast of this number is the crucial indicator in the widely known forecasting models by epidemiologists at the University of Washington and elsewhere. But in Iowa, we still do not have a forecast, and social distancing policy appears now to be hostage to an unexplained and backward-looking indicator. If that percentage continues to be low, or to fall, despite daily increases in cases, deaths, and hospitalizations, we may not see another region get to the magic number of 10.