INDIANAPOLIS -- Using the results of the first U.S. statewide random sample study of SARS-CoV-2 prevalence, IUPUI researchers calculated the first generalizable infection fatality rate for COVID-19 by age, race, ethnicity and sex.
As many COVID-19 deaths occur among residents of nursing homes, the study is the first to determine the probability of death from the infection of SARS-CoV-2, the novel coronavirus that causes COVID-19 disease, among people not living in institutions such as nursing homes or prisons. It was recently published in the Annals of Internal Medicine.
Researchers from the Richard M. Fairbanks School of Public Health and the IU School of Medicine found that age -- more than race or sex -- determines how deadly the virus is. People over 60 years of age had an infection fatality rate of almost 2 percent, or one death for every 50 people who get infected. This infection fatality rate for COVID-19 is approximately 2.5 times deadlier than seasonal flu for the same population.
"Hoosiers who are 60 and older are facing a higher possibility of death if they contract COVID-19," said Justin Blackburn, lead author and associate professor at the Fairbanks School of Public Health. "While the overall infection fatality rate is relatively low in other age groups, the long-term outcomes are not yet known. Furthermore, infected individuals who are asymptomatic can unknowingly transmit the virus to someone at increased risk."
To determine the infection fatality rate, the researchers combined prevalence estimates from the first phase of Indiana's statewide random sample study with confirmed COVID-19 deaths in the state. When testing concluded on April 29, Indiana had recorded 1,099 COVID-19 deaths; however, 495 of those deaths occurred in noninstitutionalized populations. Nursing home residents represented 54.9 percent of Indiana's deaths on that date.
Using the noninstitutionalized population, researchers determined the overall infection fatality rate for Indiana to be 0.26 percent.
The infection fatality rate for Hoosiers 12 to 40 years old is 0.01 percent (children under 12 were not included in the study). That rate increases to 0.12 percent for those who are 40 to 59 years old.
"These are the first precise estimates that allow us to determine the increased risk of death among people over 60 years old," said Nir Menachemi, senior author on the study and professor and Fairbanks Endowed Chair in the Fairbanks School of Public Health. "Previous studies determined the fatality rate based on case counts, which are known to undercount infections. We looked at other factors such as race, ethnicity and sex, but the greatest predictor of death is age."
The researchers also found that the infection fatality rate for nonwhite people is more than three times that for white people, despite the average age of COVID-19 deaths for nonwhite people being 5.6 years younger.
"Based on our research, we believe we have one of the most accurate and generalizable COVID-19 infection fatality rates in the U.S.," Menachemi said. "Deaths can be prevented by reducing the number of people who get infected, and physical distancing, wearing a mask and avoiding crowded spaces are known to help reduce infections."
COVID-19 resources for journalists
Looking for more Indiana University expertise related to the novel coronavirus? Find the latest list of IU scientists, researchers and clinicians who are available to discuss a wide range of topics, such as COVID-19's impacts on our physical and mental health, the economy, politics, globalization, and more. This resource is updated as we identify more experts to share with the media, so please check back often.
About IU Research
IU's world-class researchers have driven innovation and creative initiatives that matter for 200 years. From curing testicular cancer to collaborating with NASA to search for life on Mars, IU has earned its reputation as a world-class research institution. Supported by $854 million last year from our partners, IU researchers are building collaborations and uncovering new solutions that improve lives in Indiana and around the globe.