Hospitalization data right now seems to be one of the most critical signals that a COVID-19 outbreak in a region is getting serious. However, hospitalization data is really hard to analyze for a number of reasons:
- Hospitals don’t like to share data. In many cases in the United States (including Arizona) there was no hospitalization data during the first part of COVID-19. This was not the case with European countries. I can make a number of guesses about this including Health Information Privacy (HIPAA), inconsistent data collection, and even a sense of unwillingness by private and public hospitals alike to reveal too much about their business. However, with COVID-19 there seems to be a renewed sense that hospitals are a public good and need to be more transparent. Arizona has a new executive order (23-2020) governing the reporting of COVID-19 data.
- There doesn’t seem to be a strong central governance around hospitalization data. Before COVID-19 this was always what I assumed that CDC did, but now I think it’s just a function of the state’s Health Department. I think that if CDC created guidelines and reporting rules, we would have much richer and much more predictive data sets around the health of people in the US. Until then, however, it requires someone to clean data, hand-build datasets, etc., to extract useful information.
- Hospital data tends towards the anecdotal side. I have had many forwards from people on LinkedIn or Facebook that came from the cousin of their sister-in-law, who is a surgeon in New York explaining how overwhelmed the ICU is there in whatever town they serve. Then an hour later I get another forward from some connection in the very next county in New York explaining why their hospital has no COVID cases. This is very, very common. I think some of this is due to the above lack of transparency in hospitals, where data is even hidden from employees. I’ve had more than one person who works in a hospital in Arizona tell me at some point during the COVID-19 outbreak that there is only around XX people in the COVID ward right now — “But don’t tell anyone”. I don’t understand the perceived secrecy of this data, but due to the secrecy and poor data reporting, the ancecdote tends to carry the day. Until the next day when the opposite story comes out.
- Hospitalizations classified as COVID-19 may not have initially sought treatment for COVID. Florida is starting to run into a new kind of COVID-asymptomatic hospital patient who seeks care for an unrelated issue (broken leg, etc.) and then is tested and found to have COVID-19. This is challenging. Does the patient need to go to the COVID ward? Initially, it seems that yes, they were, but now the state is starting to handle these patients differently (and save the COVID ward for those with COVID symptoms). This is unlikely to be affecting ICU bed numbers, of course, but is possibly affecting inpatient bed counts (which are already reaching maximums as well).
- The hospital business and processes are not well understood by the layman, even by the hospital employee at times. This results in lack of understanding of the real meaning behind a data visualization.
Overview of Arizona ICU Bed Management during COVID-19
One thing that is very interesting to me is ICU bed management. Obviously hospitals want to leverage their invested ICU bed capital to make money. This would seem to require limited excess capacity in the ICU — i.e., most beds full most of the time. During COVID-19 one of the earlier stories was how COVID would overrun the ICU’s at most hospitals. I believe this did happen to an extent in New York, but it hasn’t happened yet in Arizona. COVID-19 patients are still less than 40% of all the ICU beds occupied in Arizona, but the number has been growing. See the chart below which compares the percentage of all occupied ICU beds that have a COVID-19 patient in them.
Thoughts:
- It seems like the COVID patients peaked as a percentage of the total ICU bed population in mid-April and then gradually tapered off until the lockdown easing was fairly much complete. We then see acceleration in cases drive up the percentage of COVID-19 patients to near 40%. Note there is still 15+% unoccupied ICU beds (though I’m not sure if they’re in the right places). But clearly, whoever the non-COVID patients in the ICU are, they’re decreasing. There may be an element of elective surgeries in the non-COVID ICU population, but I don’t think they’re as many as usual.
- I can’t fully get my arms around what this chart is telling me, other than perhaps it shows that hospitals know how to manage their ICU bed resources. The total percentage of ICU beds filled in the state has gone from 74% around 5/21 to about 85% today (total about 130 beds). They have done this while COVID-19 cases in the ICU have increased by about 230 people (hence, the now-higher percentage of COVID patients in ICU beds). I don’t know how they made up those extra 100 people, but they did it somehow. They have some margin to work with, I suppose, because even today, 60+% of all inhabitants of the ICU are non-COVID.
- This management is why the increase in hospital bed numbers has been linear while the COVID-19 case growth has been exponential. Here’s a view of hospitalization just compared with the numbers of 65+ COVID-19 cases. Note that the 65+ group which looks pretty linear when compared to the 20-44 age group cases still looks exponential when compared to the hospitalization (especially the ICU) rates.
