With social distancing and strict lockdowns around the world showing some success in “flattening the curve” of the coronavirus pandemic, leaders are starting to make tough decisions regarding when and how to reopen. But those decisions are even harder due to the lingering uncertainty around COVID-19, says a new Event Brief from Karen Clark & Co. (KCC).

Until there is more widespread testing, it is impossible to calculate the true infection rate of COVID-19, KCC said, which also makes it impossible to determine the fatality rate of those infected. Also in question is why certain locations have become hotspots while others have been much less impacted.

KCC said its analysts are collecting data from the Centers for Disease Control and state health departments and will be releasing monthly Event Reports. Since the term “fatality rate” has a specific meaning with respect to pandemics and cannot yet be reliably calculated, KCC is instead looking at fatalities relative to population. The Event Brief presents data collected as of April 27, 2020.

KCC’s data for April shows wide variation by geography. While the United States has experienced the highest number of confirmed cases and deaths from COVID-19 (1,003,974 cases and 52,428 deaths of as April 30, according to the World Health Organization), the country only comes in at No. 9 when the numbers are looked at relative to population. By population, Belgium has seen the highest death rate from COVID-19, with around 600 deaths per million people as of April 26 compared to the U.S. at around 150.

Within the U.S., there is also a wide variation between states, with seemingly no correlation between how early a state lockdown was imposed and the fatalities per population. As expected, New York is by far the state with the highest death rate, with around 900 deaths per million people, followed by New Jersey (between 650-700 deaths per millions) and Connecticut (approximately 550). The majority of states have death rates below 200 per million, with eight states (Alaska, Arkansas, Hawaii, Montana, South Dakota, Utah, West Virginia and Wyoming) having less than 20 deaths per million.

KCC noted that no attempt has been made to adjust for potential inconsistencies due to the variations in how countries and states collect and report their data.