COVID-19 Hospitalizations Are on the Rise — What You Should Know (Part 3)
How to think about hospital/ICU occupancy
This article belongs to a three-part series written for anyone that is looking to understand why experts are expressing concern about rising COVID-19 hospitalizations. Part one explains what the number of hospitalized patients actually means, part two explains why hospital bed distribution is important, and part three covers the nuances of hospital and ICU occupancy.
What is hospital/ICU occupancy and why does it matter?
The concept of hospital/bed occupancy predates the COVID-19 pandemic, it reflects:
- availability of medical resources (the supply),
- number of patients in need of hospitalization (the demand), and
- how quickly patients are treated and discharged from the hospital (patient turnover)
Aside: each of these merit further discussion, but that’s out of scope for this series.
In the context of the COVID-19 pandemic, occupancy is a metric used to identify regions where the number of patients requiring hospitalization exceeds the available resources.
What is the usual/normal occupancy rate?
Based on historical data: approximately 64% of hospital beds in the U.S. were occupied at the start of the COVID-19 pandemic.
- U.S. hospital occupancy between 2000 and 2017 hovered around ~64%. (Note: this is a national figure, which means that individual hospitals may have reported higher or lower occupancy rates)
- We previously mentioned that there are 792,417 staffed beds in community hospitals (i.e. those that serve the general public).
- Taken together, we estimate that ~285,270 total hospital beds were available across the entire United States at the start of the pandemic.
How is hospital/ICU occupancy calculated?
Occupancy is calculated by dividing the number of patients (the numerator) by the total number of staffed beds (the denominator).
As simple as it may seem, this metric requires thoughtful interpretation — especially when the value is plotted over time. That’s because the numerator and denominator change over time — and they do so independent of one-another. We’ve already covered how the numerator evolves over time; so let’s briefly discuss how the total number of staffed beds (denominator) is subject to change from-day-to-day, week-to-week, or even month-to-month.
The total number of staffed beds isn’t a basic count of physical beds: it’s an all-inclusive metric that reflects the number of patients that can be safely admitted to the hospital (or ICU).
In this context, safely means that all of the following are available (and at-hand):
- A physical bed
- medical supplies and equipment
- clinical staffing
Each of these these factors can impact the total number of staffed beds, as I’ve outlined in the following table:
When hospital (or ICU) occupancy is greater than 100%, it simply means that physical beds and staff were added.
How does this fit into the big picture?
In the table (above) I highlighted 3 boxes that speak to the big picture:
- COVID-19 can decrease the number of staff available to care for patients. Getting replacements/substitutes for doctors and nurses is easier said than done — that’s why it’s imperative that we provide them with personal protective equipment (PPE): to keep them on the job.
- The way to increase PPE supply is to increase manufacturing and accelerate its delivery to hospitals across the country.
- Therefore, in order to protect our most valuable asset (healthcare workers) we need a whole-of-government approach that leverages the Defense Production Act to the greatest extent possible and we need a supply chain that is coordinated at the federal level to ensure that supplies are distributed as soon as they are manufactured— neither is currently happening on a consistent basis.
What does success look like?
Texas Medical Center (TMC) serves as an example of a well-managed COVID-19 response — albeit at a hyperlocal level. Through a lot of hard work and coordination across state and local agencies, TMC is able to publish a near real-time dashboard of ICU capacity and occupancy.
TMC illustrates what is possible, and what we should expect from every hospital across the country.
Key takeaways
- Hospital/ICU occupancy is a metric used to identify regions where COVID-19 is a strain on medical resources.
- The denominator is the total number of staffed beds — this value changes on a daily, weekly, and monthly basis
- Interpreting plots of hospital/ICU occupancy over time requires that we bear in mind that both the numerator and denominator change over time.
- When everything is working in concert, it is possible to know exactly which hospitals have sufficient capacity, and which hospitals are under-resourced.
Another way to say it
As it relates to COVID-19, occupancy is the most valuable metric available because the numerator and denominator are mission-critical metrics in their own right. We need access to the underlying data in order to tease apart all of the different factors that come into play.
I’m considering adding another part to this series that explains how the underlying data are collected and reported. If you’re interested in seeing this article, please “clap” or leave a comment.
