17 July 2020

Lower COVID-19-related mortality rates in the United States: why and what does it mean?

While confirmed cases across the United States continue to rise significantly, official deaths have thus far not followed suit, perhaps pointing to a considerably lower mortality rate than initially estimated.

As confirmed cases across the United States continue to rise to record levels, official deaths have thus far not followed suit, indicating a significantly lower mortality rate than previously believed. Should this trend persist, officials may have to re-assess how to manage COVID-19-related restrictions.

In late April and early May, COVID-19 deaths in the United States peaked at approximately 3,000 per day, which corresponded to around eight percent of confirmed infections in the country. However, in June and July, deaths have averaged between 600 and 700 hundred per day and are trending downwards despite massive increases in the number of known cases, including unprecedented numbers in Texas, Arizona, California and Florida.

Health experts have attributed this fall in mortality to several factors; widespread testing, better treatment options, younger demographics of those infected and potential mutations to the virus itself, among other theories. However, looking towards the rising case counts rather than falling deaths, authorities in dozens of states have re-imposed or instituted new measures in hope of stemming the growing tide of COVID-19 infections. Such efforts include mandatory quarantines for inter-state travellers, requiring face masks in public, and continued restrictions on non-essential businesses.

This has likely occurred in part because health officials have remained wary of the low death figures. The lag between a positive COVID-19 diagnosis and corresponding death can take up to a month to show up in the statistics. Meanwhile, the surge in cases, according to many measures, began in mid June, meaning that a spike in associated fatalities may remain just around the corner. Moreover, the potential also exists for individuals under 40, who now make up the majority of new infections, to carry the disease into more vulnerable populations, resulting in a further increase of deaths.

Nonetheless, should the current lower mortality rates persist, policy makers may face pressure from constituents to again reverse course and proceed with reopening plans. Anti-lockdown protests of the type that were seen in state capitals and urban areas across the country, particularly in April and May, could once again manifest. However, to date, most policy makers have stood firm in their cautious approach, signaling that they are likely taking into account factors other than the mortality rate in their COVID-19-related decision making, an approach that seems likely to continue.