PODCAST – 2020 Final Death Statistics: COVID-19 as an Underlying Cause of Death vs. Contributing Cause

January 7, 2022

https://www.cdc.gov/nchs/pressroom/podcasts/2022/20220107/20220107.htm

HOST:  NCHS closed out the year in December with the release of final data on deaths in the United States for 2020.  As in past years, these final death statistics focus on conditions or injuries that are listed as the underlying cause of death on the death certificate, and do not include conditions or injuries listed as a contributing cause on the death certs. 

Many of the 2020 findings had been released previously, in preliminary or provisional form:  The final number on life expectancy showed a decline of 1.8 years in 2020.  The final overall death rate in America rose from 715 deaths per 100,000 in 2019 to 835 per 100,000 in 2020 – a nearly 17 percent increase.  Death rates increased for 6 of the 10 leading causes of death in 2020, including a nearly 17 percent increase in deaths from accidents or unintentional injuries… as well as a nearly 15 percent increase in deaths from diabetes.  Meanwhile, death rates decreased for 2 leading causes of death – cancer and chronic lung disease – and remained unchanged for another cause: kidney disease.  Also, suicide fell out of the top 10 leading causes of death in 2020 after the number and rate of suicide dropped for a 2nd consecutive year.

And of course there was a new entry to the list of 10 leading causes of death in 2020.  COVID-19 was the 3rd leading cause of death in 2020, with nearly 150,000 more deaths than the 4th leading cause of death, accidents, and over 250,000 fewer deaths than the 2nd leading cause of death, cancer.  The final, official tally of COVID-19 deaths in the U.S. for 2020 was 350,831.  CDC had reported a higher number of deaths from its case surveillance reporting system, and NCHS had also posted a higher number on its web site, closer to 385,000 deaths – which included any death mentioning COVID.  The official 350,831 COVID-19 deaths for 2020 reflects deaths in which COVID was the underlying cause of death.

Joining us today to talk about these 2020 numbers for COVID-19 numbers, as well as the difference between tracking underlying causes of death and contributing causes of death, is Mortality Statistics chief Robert Anderson.

HOST:  The final data for 2020 show over 350,000 deaths from COVID-19, meaning the virus was the underlying cause of death.  Can you explain what the underlying cause of death means?

ROBERT ANDERSON: The underlying cause of death is the condition that initiated the chain of events leading to death.  When the death certificate is filled out, the person who’s reporting the cause of death is asked to identify a chain of events, sort of a causal pathway, working from the immediate cause back to the underlying cause.  So an example of a chain of event or pathway would be viral pneumonia due to COVID-19.  That’s a causal pathway – COVID-19 causes viral pneumonia which then would kill the person, so COVID-19 in that instance is considered the underlying cause of death – that condition that started everything forward.  And the reason why we tend to focus on the underlying cause is because that’s the condition that’s considered most amenable to public health prevention, the idea being that if you can prevent the underlying cause then you can prevent the entire chain of events from occurring.

HOST: Now there might be some confusion because the number that had been reported for 2020 was close to 385,000 deaths.  So what about those other (almost) 34,000 deaths that some people thought were COVID-19 deaths but aren’t included in this latest tally?

ROBERT ANDERSON:  Right, so the 385,000 deaths that we would refer to as “involving COVID-19.” The other 34,000 would be deaths in which COVID-19 was a contributing factor but not the underlying cause.  So it may have exacerbated an existing disease or it may have contributed in some way but it wasn’t what initiated the chain of events leading to death.  And the person who is certifying the cause of death – usually it’s a physician, medical examiner, or coroner – has to determine what role COVID-19 played in causing the death, and this is essentially three options: it was the underlying cause and it initiated that chain of events; it was a contributing factor and played some role but it wasn’t the underlying cause; or it wasn’t a factor at all, in which case it shouldn’t be reported on the death certificate.

HOST: OK so it seems like there’s a fine line there and this sort of prompts another question:  In the new 2020 final data, we see significant increases in deaths from diabetes, for example, also from Alzheimer’s disease… heart disease… and those are the underlying cause of death so is it possible that some of those deaths, COVID-19 was listed as a contributing factor?

ROBERT ANDERSON:  Sure it’s likely, actually, that for some of those conditions COVID-19 was listed as a contributing factor, and it may have been a contributing factor in cases in which COVID-19 wasn’t listed as well – particularly in the beginning of the pandemic back when we didn’t know very much about the disease and when there wasn’t widely available testing.  It’s possible that some of those deaths are actually COVID deaths but were attributed to those other causes.  So the increase may be COVID-related.  There is also this other category that’s sort of important to recognize as well, and these are cases in which the death may have been related to the pandemic but not to the virus specifically.  This would be cases where people perhaps didn’t get the care that they needed for whatever reason – either they were afraid to go to the hospital or the doctor or they weren’t able to get into the doctor.  Particularly with a disease like diabetes that requires a fair amount of maintenance and monitoring.  If people are not going to the doctor to get checked out they’re gonna be at higher risk of dying.

HOST: So again, for those who might be confused about this, obviously with COVID-19 you have a very wide spectrum of severity – you’ve got people who may have had it but never knew they had it, or people who have tested positive but never had any symptoms, to the other end where people are severely ill.  How is it determined on the death certificate for COVID to be just a contributing cause?  It would seem like, wouldn’t it be like one or the other?  Either it was an underlying cause or didn’t really play a factor?

ROBERT ANDERSON:  Well it’s a complicated issue.  So you could have for example somebody with COVID who has symptoms, is symptomatic, but the symptoms aren’t particularly severe, but in a case with somebody with like chronic obstructive pulmonary disease or somebody with a heart condition, a serious heart condition, even fairly mild COVID symptoms could sort of push them over the edge and then the certifier has to make a judgment as to what role COVID played in that scenario.   And it’s not not always easy – sometimes it can be quite straightforward, other times not so much, particularly when you have somebody who has multiple serious chronic diseases or people who perhaps are terminally ill. The certifier has to decide what caused that person to die when they did and in some cases it might be that COVID caused them to die when they did, but it might also be a case where COVID just sort of made things worse and they died from the pre-existing condition.  It can be a difficult decision to make.

HOST: I know I’ve asked you this one before but just again to clarify: If someone is admitted to the hospital with an injury – a car accident for example – and they are tested for COVID and test positive, and then they die from their injuries in the crash –COVID would not be a “contributing cause” on the death certificate correct?

ROBERT ANDERSON:   In most cases I think not, but it is possible that COVID could complicate the clinical situation such that it makes survival less likely.  It would depend on the severity of the injuries – maybe the person comes in and they’ve got a very severe injury and they simply test positive for COVID and there are no symptoms that are likely be incidental to death.  But if you had somebody who let’s say had chest trauma from the car accident and they were, they’re struggling to breathe already… They get COVID in the hospital and they’re showing some symptoms… there, it could contribute.  So it’s really – the certifier has to look at the whole clinical picture and then make a judgment as to whether COVID played a role and then what role it played in the death, if they determine that it played a role.

HOST:  In looking at some other examples the one that comes to mind would be influenza –does influenza turn up a lot on death certificates as a contributing but not an underlying cause of death?

ROBERT ANDERSON:  Not very often – influenza is substantially underreported on death certificates to begin with.  It’s a little better now than it used to be with the rapid testing, but very often when people die from the flu they’re dying of the complications of the flu, and often after the point at which it can be determined that they had the flu.  So somebody gets the flu, they’re at home for seven to 10 days with that, they develop a secondary infection, bacterial infection, let’s say bacterial pneumonia, and struggle with that for a few more days and then go to the hospital.  Even if they’re tested for the flu they’re not going to test positive, flu is not gonna show up, so it can be very difficult unless the certifier knows that the person had the flu and understands the chain of events to figure out what happened.  So I think we’d have similar issues with COVID if COVID wasn’t so prevalent.  And if the flu was a lot more prevalent and we did a lot more testing for the flu, I think it would tend to show up on death certificates more often.  Again, it goes to trying to figure out what the chain of events looks like and what initiated that chain of events.  And the certifier needs some sort of evidence that the flu was a factor and if they don’t have it, they’re not likely to report it on the death certificate.  So what we end up with is, we end up with a few thousand deaths a year where the flu is reported on death certificates, where modeling analysis show that it’s more like 30 to 60,000 depending on the severity of the flu season.

HOST:  Are there any other conditions which often turn up as “contributing” but “not underlying?”

ROBERT ANDERSON:  Yeah I mean diabetes is one of those conditions.  If you look at the total number of diabetes deaths where diabetes is the underlying cause, you see, well just take 2020 for example, the number is about 100,000 deaths but if we look at how often it’s actually reported on the death certificate we see a whole lot more.  Something on the order of – I don’t know what the number is for 2020 at this point but in in previous years it’s been somewhere on the order of 250,000 cases.  So diabetes is one of those conditions that frequently shows up as a contributing factor and it certainly does often contribute, it complicates the clinical picture and makes survival a lot less likely in many instances.  It’s also one of those conditions where it’s hard to understand for sure where it fits in the chain of events, unless somebody has sort of a hyper osmolar reaction or something like that, they kinda have to figure out – OK, well, this person had diabetes, it wasn’t well controlled, and they died from stroke, what role did diabetes play if any?  And it likely would have played a role because it tends to make cardiovascular diseases like heart disease and cerebrovascular disease worse. 

HOST: So for the 2020 data then there could be some diabetes deaths where COVID-19 was a contributing factor.  And it could also be the opposite, right?  Where it could be a COVID-19 death where diabetes was maybe a contributing cause?

ROBERT ANDERSON:  Sure yeah, I mean, we do know people with diabetes are very susceptible to severe disease and COVID.  And so it’s likely in many cases that you would see diabetes reported along with COVID on the death certificate, as a contributing factor.

HOST:  Just one more question about the contributing causes.  So then, that section of the death certificate would also be where contributing health behaviors — or unhealthy behaviors more likely  — would that be where, like, smoking, alcoholism, drug abuse… would that be listed as a contributing cause assuming it wasn’t like an overdose or something like that?

ROBERT ANDERSON:  Yeah it could be and we do see that.  It’s not reported very consistently though – a lot of certifiers don’t like to list behaviors on the death certificate.  They want to report clinical conditions, diseases, or injuries, and so they will often leave off sort of behavioral type things.  So while we do see it – you can see smoking reported, for example, and there’s a checkbox item as well that asks the certifier of tobacco played a role or not.  That’s one of the reasons why we added that checkbox was to try to capture that information because it wasn’t reported consistently on the death certificate.  We do see things like drug abuse and alcohol abuse reported on the death certificate but normally if alcohol abuse contributed to, say, cirrhosis of the liver and killed someone, normally the certifier would report alcoholic cirrhosis and so the alcohol abuse would be implied there.

HOST:  Any other points about this you feel are important to note?

ROBERT ANDERSON:  I think it’s important to note – you mentioned the 385,000 deaths that we were reporting in our surveillance website and compared with the 350,000 underlying cause deaths.  And some have asked questions about that and my answer typically is that for surveillance purposes we like to cast a slightly wider net, because we want to get a better sense for the impact of the disease or the pandemic on overall mortality.  But when we start to really boil down the numbers and start comparing causes of death, we need to have a single cause reported for each person and that’s the underlying cause of death.  Because we don’t want to double-count deaths in our in our tabulation so we limit to the underlying cause when we’re ranking leading causes, for example, or when we’re creating a table of various causes of death.  But for surveillance purposes, when we’re trying to capture the impact of the disease we cast a slightly wider net and so we look at both underlying and contributing factors.

HOST:  Thanks for joining us again Dr. Anderson.

ROBERT ANDERSON:  Happy to do it. 

(MUSICAL BRIDGE)

HOST: NCHS capped the year with four more reports released in the final week of 2021.  The first report focused on emergency department visits to people with mental health disorders, featuring data from the National Hospital Ambulatory Medical Care Survey.  A second report looked at pre-pregnancy body mass index and infant outcomes, showing that infants fared better among women who were at normal weight prior to their pregnancy.  A third report also looked at pregnancy – in particular, maternal and infant health outcomes among women who had confirmed or presumed COVID-19 during their pregnancy.  Data from 14 states and DC were examined for this study.  The fourth and final study from NCHS in 2021 featured the final, official numbers of drug overdose deaths in the U.S. for 2020, a report that is updated annually.


NEW FEATURE: Provisional 2020 and Partial 2021 Mortality Data Available on CDC WONDER

December 7, 2021

CDC WONDER now includes provisional 2020 and partial 2021 mortality statistics by multiple cause of death at the national, state and county level. Data are based on death certificates for U.S. residents.

Multiple Cause of Death (Provisional)


Sepsis-related Mortality Among Adults Aged 65 and Over: United States, 2019

November 10, 2021

NCHS releases new report that describes sepsis-related mortality among adults aged 65 and over by age, sex, race and Hispanic origin, and urbanicity.

Key Findings:

  • Sepsis-related death rates for adults aged 65 and over varied from 2000 through 2019 but generally declined over this period.
  • Among adults aged 65 and over, sepsis-related death rates in 2019 increased with age; rates were about five times higher among adults aged 85 and over (750.0 per 100,000) compared with adults aged 65–74 (150.7).
  • In 2019, sepsis-related death rates for adults aged 65 and over were highest among non-Hispanic black adults (377.4 per 100,000) compared with non-Hispanic white (275.7), non-Hispanic Asian (180.0), and Hispanic (246.4) adults.
  • Among adults aged 65 and over, sepsis-related death rates in 2019 were higher in rural areas compared with urban areas.

Q & A with Author: Mortality Profile of the Non-Hispanic American Indian or Alaska Native Population, 2019

November 9, 2021

Questions for Elizabeth Arias, Health Statistician and Lead Author of “Mortality Profile of the Non-Hispanic American Indian or Alaska Native Population, 2019.”

Q: Is the first report on non-Hispanic American Indian or Alaska Native (AIAN) mortality? 

EA: Yes. This is the first report that NCHS publishes exclusively on non-Hispanic AIAN mortality.  Limited mortality statistics for this population has been included in our standard mortality reports.


Q: Why is there an issue of misclassification of race and ethnicity on U.S. death certificates for the AIAN population?

EA: We do not know exactly why individuals who self-identify as AIAN while alive have a higher rate of being classified as a different race on their death certificates than other racial and ethnic populations.  What we know is that funeral directors who are responsible for filling out the demographic portion of the death certificate may rely on visual observation rather than ask family informants the race of decedent.  An important factor in visual misclassification is that the proportion of multiple race individuals, predominantly individuals who identify as both AIAN and white, within the AIAN population is relatively large.   


Q: Are there any differences in the leading causes of death order for the AIAN population compared to U.S. overall?

EA: Most of the 15 leading causes of death experienced by the non-Hispanic AIAN population are the same as those affecting the total US population.  However, there are important differences.  For the non-Hispanic AIAN population, homicide is the 13th leading cause of death whereas homicide is not one of the 15 leading causes of death for the total population. The order of the 15 leading causes of death differs for the non-Hispanic AIAN population.  Of note, Chronic liver disease and cirrhosis is the 4th leading cause for this population but the 11th cause for the US overall, Suicide is the 8th vs 10th cause, and Alzheimer is the 11th vs 6th cause.


Q: Is there any trend data on life expectancy for the AIAN population prior to 2019?

EA: We publish death counts, and age-specific and age-adjusted death rates for the AIAN population annually in our final mortality reports.  However, these estimates are not adjusted for misclassification.  The most reliable mortality estimates published prior to this report were based on a linkage of Indian Health Service (HIS) patient registration data and vital statistics mortality data covering years 1990-2009.  The data covered 65% of the non-Hispanic AIAN population, those living in Contract Health Service Delivery Areas of the IHS.  A special issue of the American Journal of Publish Health was published (see American Journal of Public Health – Volume 104, Issue S3 (aphapublications.org).


Q: What is the main takeaway message from this report?

EA: Racial and ethnic health and mortality disparities in the US are profound.  The non-Hispanic AIAN mortality profile resembles that of some of the populations in the poorest, under developed countries in the world.


QuickStats: Age-Adjusted Rates of Firearm-Related Suicide, by Race, Hispanic Origin, and Sex — National Vital Statistics System, United States, 2019

October 15, 2021

mm7041a5-f

In 2019, among males, non-Hispanic White males had the highest age-adjusted rate of firearm-related suicide at 15.8 per 100,000 population, followed by non-Hispanic American Indian or Alaskan Native males (11.2), non-Hispanic Black males (6.9), Hispanic males (4.6), and non-Hispanic Asian or Pacific Islander males (3.2).

Among females, non-Hispanic White and non-Hispanic American Indian or Alaskan Native females had the highest rates (2.6 and 2.2, respectively), followed by non-Hispanic Black females (0.8), Hispanic females (0.6), and non-Hispanic Asian or Pacific Islander females (0.4).

Males had higher rates than females across all race and Hispanic origin groups.

Source: National Vital Statistics System, Mortality Data, 2019. https://www.cdc.gov/nchs/nvss/deaths.htm

https://www.cdc.gov/mmwr/volumes/70/wr/mm7041a5.htm


NCHS Releases Latest Quarterly Provisional Mortality Data Through Full-Year 2020

June 8, 2021

NCHS has released the latest quarterly provisional mortality rates for the U.S., through full-year 2020 for most causes of death. 

Estimates are presented for 15 leading causes of death plus estimates for deaths attributed to coronavirus disease 2019 (COVID-19), drug overdose, falls for persons aged 65 and over, firearm-related injuries, human immunodeficiency virus (HIV) disease, and homicide. 

The data is featured on an interactive web site dashboard at: https://www.cdc.gov/nchs/nvss/vsrr/mortality-dashboard.htm.

NCHS has also released state maps showing COVID-19 death rates for provisional quarter 4 mortality data. You can access the 12-month ending map here and quarterly map here.


QuickStats: Age-Adjusted Death Rates for Alzheimer Disease Among Adults Aged ≥65 Years, by Sex — National Vital Statistics System, United States, 1999–2019

April 23, 2021

mm7016a5-f

The age-adjusted death rate for Alzheimer disease increased from 128.8 per 100,000 in 1999 to 233.8 in 2019.

The trend for the total population and for men and women alternated between periods of general increase and periods of stability. Rates were stable from 2016 to 2019, and in 2019 were 263.0 for women and 186.3 for men.

Throughout the 1999–2019 period, the rate was higher for women than for men.

Source: National Center for Health Statistics, National Vital Statistics System, Mortality Data, 1999–2019. https://www.cdc.gov/nchs/nvss/deaths.htm


QuickStats: Rate of Unintentional Traumatic Brain Injury (TBI)–Related Deaths Among Persons Aged 24 Years and Under, by Age Group

October 16, 2020

From 1999 to 2018, death rates for unintentional TBI among persons aged 24 years and under declined across all age groups.

During the 20-year period, TBI-related death rates declined from 3.7 per 100,000 to 1.5 among children aged 0–4 years, from 3.0 to 0.9 for children and adolescents aged 5–14 years, from 14.7 to 4.4 for adolescents and young adults aged 15–19 years, and from 14.1 to 6.9 for young adults aged 20–24 years.

For most of the period, rates were highest for persons aged 20–24 years followed by those aged 15–19, 0–4, and 5–14 years.

Source: National Center for Health Statistics, National Vital Statistics System, Mortality Data. https://www.cdc.gov/nchs/deaths.htm.

https://www.cdc.gov/mmwr/volumes/69/wr/mm6941a5.htm


QuickStats: Rates of Deaths Attributed to Unintentional Injury from Fire or Flames by Age Group and Urbanization Level

August 28, 2020

In 2018, the death rates attributed to unintentional injury from fire or flames were lowest among those aged 15–24 years and highest among those aged 75 years or older.

In rural areas, death rates decreased with age from 2.0 per 100,000 for persons aged 0–4 years to 0.3 for those aged 15–24 years, and then increased with age to 5.6 for those aged 75 years or older.

The pattern was similar for urban areas, where rates were 0.5 per 100,000 for persons aged 0–4 years, decreased to 0.1 for those aged 15–24 years, and then increased with age to 2.8 for those aged 75 years or older.

Across all age groups, death rates were approximately two to four times higher in rural areas compared with urban areas.

Source: National Center for Health Statistics, National Vital Statistics System, mortality data; 2018. https://www.cdc.gov/nchs/nvss/deaths.htm.

https://www.cdc.gov/mmwr/volumes/69/wr/mm6934a8.htm 


Racial and Ethnic Differences in Mortality Rate of Infants Born to Teen Mothers: United States, 2017–2018

July 31, 2020

Questions for Ashley Woodall, Health Statistician and Lead Author of “Racial and Ethnic Differences in Mortality Rate of Infants Born to Teen Mothers: United States, 2017–2018.”

Q: Why did you decide to focus on teenagers for this report?

AW: There has not been much research on infant mortality using national data that focuses on specific maternal age groups. Teenagers are an age group of particular interest because infants born to teenagers have higher infant mortality rates compared with infants born to women in older age groups. Consequently, we wanted to explore the recent patterns in infant mortality for teenagers in the United States.


Q: Can you summarize some of the findings?

AW: In 2017–2018, infants born to teenagers aged 15–19 had the highest rate of mortality (8.77 deaths per 1,000 live births) compared with infants born to women aged 20 and over. Among teenagers, infants of non-Hispanic black females had the highest infant mortality rate (12.54) compared with non-Hispanic white (8.43) and Hispanic (6.47) females. Among the five leading causes of infant death, the largest racial and ethnic difference in mortality rates was found for preterm- and low-birthweight-related causes, where rates were two to three times higher for infants of non-Hispanic black teenagers (284.31 per 100,000 live births) than infants of non-Hispanic white (119.18) and Hispanic (94.44) teenagers.


Q: Was there a specific finding in the data that surprised you from this report?

AW: We were surprised by the large racial and ethnic disparity in deaths for preterm- and low-birthweight-related causes. This finding suggests that preterm birth and low birthweight are significant contributing factors for death among infants born to non-Hispanic black teenagers.


Q: Can you explain the difference between total infant, neonatal, and postneonatal mortality rates?

AW: Infant mortality is the death of a baby before his or her first birthday. It is calculated by dividing the number of infant deaths during a calendar year by the number of live births reported in the same year. It is expressed as the number of infant deaths per 1,000 live births. Neonatal mortality rate is the death of a baby during the first 27 days after birth, per 1,000 live births. Postneonatal mortality rate is the death of a baby between 28 days to under 1 year after birth, per 1,000 live births.


Q: What is the take home message for this report?

AW: The different mortality patterns seen among infants born to teenage mothers illustrate the racial and ethnic disparities in infant mortality and suggest that preterm birth and low birthweight are major public health concerns for infants born to non-Hispanic black teenagers.