THREAD
Let's talk a little bit about COVID-19 mortality and age differences.
Firstly, it has been clear from the early days of this disease that older people (and those with preexisting conditions) are at much higher risk.
Let's talk a little bit about COVID-19 mortality and age differences.
Firstly, it has been clear from the early days of this disease that older people (and those with preexisting conditions) are at much higher risk.
Right now, 1 in 4 people over the age 80 diagnosed with COVID-19 has died, as have 1 in 7 over age 60.
That compares to fewer than 1 in 900 deaths for people under the age of 30.
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That compares to fewer than 1 in 900 deaths for people under the age of 30.
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That's not to say that COVID-19 is an easy disease for young people. Even though >99% of young adults recover, both Spain and the USA have reported that ~15% of their confirmed cases in young adults have needed hospital care.
Data for Spain shown.
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Data for Spain shown.
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For the countries that have published mortality breakdowns by age all show a similar picture that age is a severe risk factor, though with some differences.
In particular, Italy has a higher death rate in all the elderly age brackets.
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In particular, Italy has a higher death rate in all the elderly age brackets.
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It has been apparent that Italy is struggling with a higher fatality rate than other countries. Part of this is due to an older population, but the age-specific death rates above make clear that it is not just due to age.
Overwhelmed hospitals are likely a factor in Italy.
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Overwhelmed hospitals are likely a factor in Italy.
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Another interesting factor is the age distribution of the confirmed COVID-19 cases.
There is an excess of older patients and a severe deficit of young cases.
In addition, Italy & Spain show very high numbers of old patients, partially explaining their high death rates.
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There is an excess of older patients and a severe deficit of young cases.
In addition, Italy & Spain show very high numbers of old patients, partially explaining their high death rates.
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Disease severity is likely to affect the number of reported cases as many patients with mild symptoms may not seek treatment or be diagnosed.
If children often have mild or no symptoms, this might explain why so few children have been diagnosed.
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If children often have mild or no symptoms, this might explain why so few children have been diagnosed.
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Studies of household groups suggest that children who have prolonged exposure to COVID-19 are as likely to contract it as adults, though they are much more likely to have mild or no apparent symptoms.
medrxiv.org/content/10.110…
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medrxiv.org/content/10.110…
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It is possible to create an age-standardized fatality rate by calculating the expected mortality rate if one assumes that persons of any age could have contracted the disease at equal rates.
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From the age-standardized rates, it is clear that much (but not all) of the difference between nations is due to differences in the ages of the populations infected.
The average patient age in South Korea is 44, vs. 61 in Italy.
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The average patient age in South Korea is 44, vs. 61 in Italy.
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However, even after standardizing for age, Italy shows a higher death rate, likely reflecting additional factors including an overwhelmed hospital system.
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