March 20, 2020
To:

Special Joint Committee on Coronavirus Response

Re:

COVID-19 preparedness

Chair Roblan, Chair Holvey, and Members of the Committee,
For the record, my name is Peter Graven and I am lead data scientist at OHSU and an affiliated
research assistant professor of health in the OHSU-Portland State University School of Public
Health. Thank you for having me here today.
OHSU and OHA have been working together to create modeling that will help predict the
number of expected hospitalizations at OHSU, the Portland Metro and the state of Oregon for
COVID-19 patients.
It’s important to note, the modeling I will discuss today is what we used to inform the actions
we needed to take. We will be closely tracking the actual number of cases in Oregon and
updating the projections going forward, which will help us measure the impact of those actions
our communities are currently taking to reduce the spread of COVID-19.
As Dr. Jacobs said, we strongly support the social distance measures put in place by our state’s
leaders and hope they are taken seriously by Oregonians and prove effective. While we know
the actions will have an impact, due to testing lags, we do not know what the current situation
was when we acted. Indeed, simulations of the social distancing measures already taken would
show that they should be enough if the number of cases were actually as low as reported at the
time. However, because of the significant lack of available widespread testing, we know there
were a larger number of unconfirmed cases at the time the state implemented the current
measures. Therefore, those simulations will underestimate the number of hospitalizations and
likely prove to significantly underestimate the projected need for hospital capacity.
The model fundamentally comes down to straightforward math. It’s built upon two key
assumptions:
•

We expect the number of cases in Oregon to double every 6.2 days, based on trends
that have been documented elsewhere around the world.

 •

The doubling begins Feb. 1. That’s when we now believe the novel coronavirus was first
introduced in Oregon.

We assume that 19% percent or approximately one in five people who contract the virus will
need to be hospitalized. And we assume 10% of patients will need to be in an intensive care
unit with 70% of those people requiring ventilators.
Based on the experience of other health care providers around the world, we can expect the
average length of stay for a COVID-19 patient to be 14 days for normal acute care
hospitalization and 22 days for patients who need intensive care.
It is important to understand why this matters. The average length of stay for a non-COVID-19
OHSU patient is 5 to 6 days, much shorter than the 14-day average for a COVID-19 patient.
Longer length of stays put more strain on our hospital resources. The longer a patient needs to
stay in the hospital, the less capacity a hospital has to take care of newly sick patients.
We then modeled the rate of growth from the start of February out to 50 days, which
corresponds to the peak of the growth curve experienced in other regions including South
Korea. Based on those assumptions, the model shows the following:
•
•
•

The state of Oregon will need 1000 acute care hospital beds and 400 ICU beds for
COVID-19 patients by April 16. There are 1,059 ICU beds in Oregon.
The Portland metro area will need 700 acute care hospital beds and 300 ICU beds for
COVID-19 patients by April 16. There are 582 ICU beds in the Portland region.
OHSU will need 200 beds in acute care and another 80 beds in the ICU for COVID-19
patients by April 16.

This is the information we at OHSU have used to prepare for the hospital-based needs of
COVID-19 patients in Oregon. We look forward to continuing to work with the state to address
the spread of the virus and protect the health of Oregonians.
Thank you.
Peter Graven, Ph.D.
Lead Data Scientist
Oregon Health & Science University
Affiliate Research Assistant Professor
OHSU-Portland State University School of Public Health