COVID-19 and 1918 Flu Mortality in NYC 'In the Same Ballpark'

Marcia Frellick

August 13, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

A comparison of excess deaths in New York City during the beginning of the COVID-19 outbreak with excess deaths from the peak of the 1918 H1N1 influenza outbreak finds COVID-19 mortality rates jumped higher.

Jeremy Samuel Faust, MD, an emergency physician at Brigham and Women's Hospital in Boston, Massachusetts, and colleagues, found that during the peak of the H1N1 outbreak, excess deaths (the number of deaths beyond what would normally be expected for that period) were comparable to COVID-19 excess deaths in the first 2 months of the city's outbreak.

However, because death rates have dropped by half over the last century with medical advances, the relative increase in excess deaths during the COVID-19 outbreak was substantially greater than the rate during the H1N1 "Spanish flu" pandemic.

COVID-19 Mortality Jump From Baseline Was Higher

Faust told Medscape Medical News they looked at the data through two lenses.

In one comparison of all-cause mortality rates, COVID-19 is about 70% as deadly as the 1918 flu, which killed 50 million people worldwide, 675,000 in the United States.

In other words, he said, "70% as many of the people died in April of this year as died in November of 1918."

But in terms of how far the death rates jumped from pre-pandemic times, COVID-19 is worse.

The incident rate ratio for all-cause mortality during the 1918 H1N1 pandemic compared with the 3 years before jumped to almost 3 times as high (2.80).

But the incident rate ratio for all-cause mortality during the first 2 months of the pandemic in New York City compared with corresponding periods from 2017 through 2019 was more than 4 times as high (4.15).

"From the perspective of mortality, these pandemics [are] in the same ballpark," Faust said.

Figure. Deaths in New York City During the 1918 H1N1 Influenza Pandemic and the Coronavirus Disease 2019 (COVID-19) Pandemic and During the Preceding Years of Both Pandemics

The study, which used public data from the Centers for Disease Control and Prevention, The New York City Department of Health and Mental Hygiene, and the US Census Bureau, was published online today in JAMA Network Open.

The researchers calculated the incidence rate per person-months (with 95% CIs) for October and November (61 days) from 1914 through 1918, and for March 11, 2020, through May 11, 2020 (61 days). Then they divided 61-day incident rates by two to calculate person-months (incidents per capita per month).

Table. Incident Rate Ratios for All-Cause Mortality

Pandemic Period (NYC)

Incident Rate per 100K person-months

95% CI

Peak of 1918 H1N1 influenza outbreak


282.71 - 291.69

First 2 months of COVID-19 outbreak


199.03 - 205.17

Faust said the comparisons show that, "In the case of New York, this pandemic can take its place along with 1918 as potentially that severe."

Without a vaccine, he said, the numbers could hit or surpass the 1918 influenza death toll.

As to whether New York City figures are representative of the United States as a whole, Faust said, "It could be that New York, in particular, was set up for the worst-case scenario. We will only know that in the end."

The authors write, "We believe that our findings may help officials and the public contextualize the unusual magnitude of the COVID-19 pandemic, leading to more prudent policies that may help to decrease transmission by decreasing the effective reproduction number of SARS-CoV-2 and prevent the exhaustion of essential supplies of life-saving resources in the coming weeks and beyond."

The authors note that a limitation is the lack of knowledge about how many deaths from SARS-CoV-2 infection have been prevented as a result of inventions that weren't widely available 100 years ago, including standard resuscitation, supplemental oxygen, mechanical ventilation, kidney replacement therapy, and extracorporeal membrane oxygenation.

A coauthor reported working under contract with the Centers for Medicare & Medicaid Services. No other relevant financial relationships were disclosed.

JAMA Netw Open. 2020;3(8):e2017527. Full text

Marcia Frellick is a freelance journalist based in Chicago. She has previously written for the Chicago Tribune, Science News and and was an editor at the Chicago Sun-Times, the Cincinnati Enquirer, and the St. Cloud (Minnesota) Times. Follow her on Twitter at @mfrellick.

Follow Medscape on Facebook, Twitter, Instagram, and YouTube.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: