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JAMA study: 35% of excess US deaths tied to causes other than COVID-19

Since COVID-19’s spread to the US earlier this year, death rates in the US have risen significantly. But deaths attributed to COVID-19 only account for about two-thirds of the increase in March and April, according to a study. Researchers at Virginia Commonwealth University and Yale University found that, from 1 March to 25 April, the US saw 87,001 excess deaths – or deaths above the number that would be expected based on averages from the previous five years.

The study showed that only 65% of the excess deaths that occurred in March and April were attributed to COVID-19, meaning more than one-third were linked to other causes. In 14 states, including two of the most populated – California and Texas – more than half of the excess deaths were tied to an underlying cause other than COVID-19, said lead author Dr Steven Woolf, director emeritus of VCUs Centre on Society and Health.

This data, Woolf said, suggests the COVID-19 death counts reported to the public underestimate the true death toll of the pandemic in the US.

“There are several potential reasons for this under-count,” said Woolf, a professor in the department of family medicine and population health at VCU School of Medicine. “Some of it may reflect under-reporting; it takes awhile for some of these data to come in. Some cases might involve patients with COVID-19 who died from related complications, such as heart disease, and those complications may have been listed as the cause of death rather than COVID-19.

“But a third possibility, the one we’re quite concerned about, is indirect mortality – deaths caused by the response to the pandemic,” Woolf said. “People who never had the virus may have died from other causes because of the spill-over effects of the pandemic, such as delayed medical care, economic hardship or emotional distress.”

Woolf and his team found that deaths from causes other than COVID-19 rose sharply in the states that had the most COVID-19 deaths in March and April. Those states were Massachusetts, Michigan, New Jersey, New York – particularly New York City – and Pennsylvania. At COVID-19’s peak for March and April (the week ending 11 April), diabetes deaths in those five states rose 96% above the expected number of deaths when compared to the weekly averages in January and February of 2020. Deaths from heart disease (89%), Alzheimer’s disease (64%) and stroke (35%) in those states also spiked.

New York City’s death rates alone rose a staggering 398% from heart disease and 356% from diabetes, the study stated.

Woolf said he and his team suspect that some of these were indirect deaths from the pandemic that occurred among people with acute emergencies, such as a heart attack or stroke, who may have been afraid to go to a hospital for fear of getting the virus. Those who did seek emergency care, particularly in the areas hardest hit by the virus, may not have been able to get the treatment they needed, such as ventilator support, if the hospital was overwhelmed by the surge.

Others may have died from a chronic health condition, such as diabetes or cancer, that was exacerbated by the effects of the pandemic, said Woolf, VCU’s C Kenneth and Dianne Wright distinguished chair in population health and health equity. Still others may have struggled to deal with the consequences of job loss or social isolation. “We can’t forget about mental health,” Woolf said. “A number of people struggling with depression, addiction and very difficult economic conditions caused by lockdowns may have become increasingly desperate, and some may have died by suicide. People addicted to opioids and other drugs may have overdosed. All told, what we’re seeing is a death count well beyond what we would normally expect for this time of year, and it’s only partially explained by COVID-19.”

Woolf and his co-authors, Dr Derek Chapman, Dr Roy Sabo, and Latoya Hill of VCU, and Dr Daniel M Weinberger, of Yale University, state that further investigation is needed to determine just how many deaths were from COVID-19 and how many were indirect deaths “caused by disruptions in society that diminished or delayed access to health care and the social determinants of health (jobs, income, food security).”

Woolf, also a family physician, said this paper’s results underscore the need for health systems and public officials to make sure services are available not only for COVID-19 but for other health problems. His study showed what happened in the states that were overwhelmed by cases in March and April. Woolf worries that the same spikes in excess deaths may now be occurring in other states that are being overwhelmed.

“The findings from our VCU researchers’ study confirm an alarming trend across the US, where community members experiencing a health emergency are staying home – a decision that can have long-term, and sometimes fatal, consequences,” said Dr Peter Buckley, interim CEO of VCU Health System and interim senior vice president of VCU Health Sciences. “Health systems nationwide need to let patients know it is safe and important to seek care in a health emergency, whether it’s through telehealth or in person.”

Woolf, who serves in a community engagement role with the C Kenneth and Dianne Wright Centre for Clinical and Translational Research, said resources should be available for those facing unemployment, loss of income and food and housing insecurity, including help with the mental health challenges, such as depression, anxiety or addiction, that these hardships could present.

“Public officials need to be thinking about behavioural health care and ramping up their services for those patients in need,” Woolf said. “The absence of systems to deal with these kinds of other health issues will only increase this number of excess deaths.”

The research team from VCU and Yale received funding for this study from the National Centre for Advancing Translational Sciences and the National Institute of Allergy and Infectious Diseases. Both entities are part of the National Institutes of Health.

The number of publicly reported deaths from coronavirus disease 2019 (COVID-19) may underestimate the pandemic’s death toll. Such estimates rely on provisional data that are often incomplete and may omit undocumented deaths from COVID-19. Moreover, restrictions imposed by the pandemic (stay-at-home orders) could claim lives indirectly through delayed care for acute emergencies, exacerbations of chronic diseases, and psychological distress (drug overdoses). This study estimated excess deaths in the early weeks of the pandemic and the relative contribution of COVID-19 and other causes.
Methods: Weekly death data for the 50 US states and the District of Columbia were obtained from the National Center for Health Statistics for January through April 2020 and the preceding 6 years (2014-2019).1,2 US totals excluded Connecticut and North Carolina because of missing data. The analysis included total deaths and deaths from COVID-19, influenza/pneumonia, heart disease, diabetes, and 10 other grouped causes (Supplement). Mortality rates for causes other than COVID-19 were available only for underlying causes. Death data with any mention of COVID-19 on the death certificate (as an underlying or contributing cause) were used to capture all deaths attributed to the virus. Population counts for calculating mortality rates were obtained from the US Census Bureau.3,4
Observed deaths for the 8 weeks between March 1, 2020, and April 25, 2020, were taken from provisional data released on June 10, 2020.2 Expected deaths (and 95% CIs) for these same weeks were estimated by fitting a hierarchical Poisson regression model to the weekly death counts for the period of December 29, 2013, through February 29, 2020 (assembled from final data for 2014-20181 and provisional data for January 1, 2019, through February 29, 20202). The model with the optimal fit (Supplement) used a combination of harmonic functions to capture seasonality and adjusted for annual trends with a categorical year effect. The model allowed season and time trends to vary by state.
Excess deaths equaled the difference between observed and expected deaths and were summed across the 8 weeks to estimate total excess deaths. To explore increases in cause-specific mortality in jurisdictions overwhelmed by COVID-19, mortality trends for 14 grouped causes (4 reported here) were examined in the 5 states with the most COVID-19 deaths from March through April 2020 (Massachusetts, Michigan, New Jersey, New York, and Pennsylvania). Deaths in these states peaked in the week ending on April 11, 2020, and the proportional increase above baseline (weighted mean of weekly deaths over 9 weeks in January to February 2020) was measured. All calculations were performed using SAS, version 9.4.
Results: Between March 1, 2020, and April 25, 2020, a total of 505 059 deaths were reported in the US; 87 001 (95% CI, 86 578-87 423) were excess deaths, of which 56 246 (65%) were attributed to COVID-19. In 14 states, more than 50% of excess deaths were attributed to underlying causes other than COVID-19; these included California (55% of excess deaths) and Texas (64% of excess deaths) (Table). The 5 states with the most COVID-19 deaths experienced large proportional increases in deaths from nonrespiratory underlying causes, including diabetes (96%), heart diseases (89%), Alzheimer disease (64%), and cerebrovascular diseases (35%) (Figure). New York City experienced the largest increases in nonrespiratory deaths, notably from heart disease (398%) and diabetes (356%).
Discussion: These estimates suggest that the number of COVID-19 deaths reported in the first weeks of the pandemic captured only two-thirds of excess deaths in the US. Potential explanations include delayed reporting of COVID-19 deaths and misattribution of COVID-19 deaths to other respiratory illnesses (eg, pneumonia) or to nonrespiratory causes reflecting complications of COVID-19 (eg, coagulopathy, myocarditis). Few excess deaths involved pneumonia or influenza as underlying causes.
This study has limitations, including the reliance on provisional data, potentially inaccurate death certificates, and modeling assumptions. For example, modeling epidemiologic, instead of calendar, years would reduce the excess deaths estimate to 73 524.
Large increases in mortality from heart disease, diabetes, and other diseases were observed. Further investigation is required to determine the extent to which these trends represent nonrespiratory manifestations of COVID-19 or secondary pandemic mortality caused by disruptions in society that diminished or delayed access to health care and the social determinants of health (eg, jobs, income, food security).

Steven H Woolf; Derek A Chapman; Roy T Sabo; Daniel M Weinberger; Latoya Hill


[link url=""]Virginia Commonwealth University material[/link]


[link url=""]JAMA abstract[/link]

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