COVID-19 Event Risk Assessment Planning Tool

Although Thanksgiving is behind us, we are still in the midst of the holiday season. It is a festive time of year that is normally accompanied by personal and work-related social gatherings. Many people are cutting down on social events either voluntarily or due to city-wide stay at home orders like the one that was issued in Los Angeles on November 27.

However, gatherings of individuals from different households are still being organized and attended across the country. If you are thinking about organizing an event or considering attendance at an event where there will be 10 or more participants, did you know that you can estimate the chance that at least 1 COVID-19 positive individual will be present? The COVID-19 Event Risk Assessment Planning Tool uses county-level COVID-19 data, in combination with the number of attendees. To get your estimate, simply move the “Event Size” slider to approximate the number of attendees and navigate on the map to the county where the event is to take place.

While the tool is intended to be simple to use, it has limitations like any other predictive model. Since we don’t test every American on a regular basis, the actual number of COVID-19 cases is greater than the number of documented cases. It has been estimated that for each confirmed case of COVID-19, there are 10 times as many unreported cases. Another study estimates that there are anywhere from 6 to 24 times the number of unreported cases for each reported case. Hence, the COVID-19 Event Risk Assessment Planning Tool includes a variable called “Ascertainment Bias” which denotes the number of actual cases for each documented case. The tool defaults to an ascertainment bias of 5 (i.e., for each documented case, there are 5 times as many actual cases) but allows you to change it to 10.

The tool has many other features including global risk estimates, real-time US and state-level estimates, and others. Read more about the risk assessment tool in this article, or click on the “About” tab in the tool to see data sources and links to articles about the tool. Stay safe everyone!

How Much Food Do You Really Need?

Several weeks ago, people started panic buying in anticipation of sheltering in place due to the coronavirus pandemic. While toilet paper was commonly known to be in short supply, people have also been stockpiling various kinds of food items. This site provides a handy dandy food calculator to help you estimate how long your food supplies will last, given how much of each food item you have and how many months you have to feed.





Input quantities for pantry essentials like rice, tuna, pasta, chicken, and beans can be toggled between metric and imperial units. The calculator also estimates how long comfort food like coffee, beer, and ice cream will last. The calculation methodology is presented at the bottom of the site, and obviously the actual longevity of your food supplies will depend on your family’s rate of consumption. Details aside, the main point of the calculator is to remind us not to hoard.

COVID-19 Hospital Impact Model for Epidemics

As if I have not written about enough COVID-19 hospital resource calculators, I just learned about another one called COVID-19 Hospital Impact Model for Epidemics (CHIME) which was produced by Predictive Healthcare at Penn Medicine and described in a research publication in the Annals of Internal Medicine. Similar to other COVID-19 predictive models, CHIME uses a variety of inputs (hospital parameters, transmission parameters, and severity parameters) to predict hospital resource utilization. The forecasted utilization outcomes include new admissions, inpatient census, and the number of susceptible, infected, and recovered individuals in the hospital.







And as if this blog hasn’t provided sufficient coverage about hospital resource calculators, the authors of the CHIME research study compared the predictions from CHIME with those from other COVID-19 forecasting tools including this one and this one.

In conclusion, I suspect that there are many other COVID-19 hospital resource calculators out there that I haven’t covered, but it is probably unnecessary for me to continue writing about them unless they have unique features that I have not previously written about. I hope that few hospitals will exceed capacity, and for the ones that do, I hope that these kinds of forecasters had been used long ago so that hospital administrators could plan ahead for the anticipated surge in demand.

Yet Another COVID-19 Calculator

I’ve previously written about web-based COVID-19 forecasting tools like this one and this one that predict hospital resource utilization and other factors. Adding to the mix, the folks at Rush University Medical Center have created a hospital resource calculator as well.

Based on data from Johns Hopkins University Center for System Science and Engineering which I’ve also discussed, this visualization forecasts the number of cases for each state. Based on a set of variables, the calculator can also estimate hospital admissions, census, and demand for personal protective equipment.

Rather than explain all the input variables, I’ll direct you to a blog that was jointly written by the folks who created the calculator. It describes the variables as well as their units of measure which might not be immediately apparent by just looking at the site.

As with any forecast, the accuracy is only as good as the fitness between the predictive model and what is happening in the real world. The spread of COVID-19 is complex, and we still do not fully understand the reasons why some people with COVID-19 do well and others to poorly. Nevertheless, when we broaden our view from patients to populations, we can see patterns against which we can create mathematical models to estimate what might happen in the future

Forecasting COVID-19 Hospital Resource Use and Deaths

A study by the Institute for Health Metrics and Evaluation was published in MedRxiv (pronounced “Med Archive”) and forecasts the extent and timing of deaths and excess demand for hospital services due to COVID-19 in the US. Its forecast model uses data from the World Health Organization and local and national governments to estimate deaths and hospital resource utilization over the next 4 months. Hospital resource utilization is stratified by all hospital beds, ICU beds, and invasive ventilators. At a national level, resource utilization and deaths are forecasted to peak on April 16, 2020.

The projections can also be filtered down to a state level where forecasted hospital resource utilization is additionally displayed against capacity. The state-specific forecasts are displayed alongside state-mandated social distancing measures including stay at home orders, closures of schools and non-essential services, and travel restrictions. The models are also updated as new information becomes available. A FAQ page provides many additional insights into the research. Hopefully hospitals and health systems will use these forecasts to close or mitigate gaps in hospital capacity since peak volumes are only about 2 weeks away. Are the hospitals in your state prepared?

The Answer is 10.5

In recent days (maybe weeks?) I've noticed that my macOS High Sierra 10.13.5 calculator widget in the Notification Center has been defaulting to a value of 10.5:

If I clear the value, it will display 0. If I perform a calculation, it will correctly display the result. However, once I close and re-open the Notification Center, the calculator widget will display a value of 10.5.

Do you think my iMac is trying to tell me something? Will Los Angeles County sales tax increase to 10.5%? Should I use the numbers 10 and 5 next time I play the lottery? Will the world end on October 5?