Tuesday, May 26, 2020

15 Average Years of Life Lost for each COVID-19 death

The following is a very rough estimate, which would be subject to refinement or correction, but I believe it is reasonably accurate.  

Here are some calculations to show approximate average years of life lost for each COVID-19 death in the population.  They are based on mortality statistics of COVID-19 deaths, 
which shows that about 49% of people dying were age 75+ (each of whom lost 6 years of life on average); 25% of people dying were ages 65-75 (each of whom lost about 15 years of life on average); 22% of people dying were ages 45-64 (each of whom lost about 30 years of life on average), 4% of people dying were ages 18-44 (each of whom lost about 55 years of life on average), and 0.05% of people dying were younger than 18 (each of whom lost about 70 years of life on average).  

Therefore the average years of life lost for each COVID-19 death is 
(0.49 * 6) + (0.25 * 15) + (0.22 * 30) + (0.04 * 55) + (.0005 * 70) = 15.525

So each COVID-19 death in the population leads to an average loss of 15 years of life.

The calculation is based on tables of COVID-19 deaths by age, all of which give quite similar numbers, combined with life expectancy tables (in this case from Statistics Canada).  

The US population therefore, in just 4 months time has had about 1.5 million years of life lost from COVID-19 (probably an underestimate), which is about as many years of life lost as from all the murders in the US in 2 years' time.

Reference for murder YLL statistics: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5607680/

Update:  through the course of 2020, there were about 375 000 COVID-related deaths in the US, representing over 4 million years of life lost, which is a similar impact on the population as 
all of the murders in over 5 years' time.  

Saturday, May 2, 2020

Why strict social distancing and massively increased testing are important to solve the COVID-19 problem

There are various clear arguments about why social distancing is important in managing the pandemic.

Most would agree that obviously  distancing will reduce spreading.  But many people might wonder why it is necessary to continue social distancing even when case numbers are dropping, or when the situation appears to have improved, especially when distancing measures are causing such hardship.

When considering any sort of physical system or intervention, it is often interesting, logically, to consider what happens when an intervention is applied at the theoretical extremes.

Thought experiment #1: the two hypothetical extremes of social distancing

The two extremes for social distancing would be the following:

case #1) every person on earth (all 7.8 billion of us) would maintain over 2 metres (6 feet) of distance from every other person on earth, continuously for the next 4-6 weeks.

case #2) every person on earth (all 7.8 billion of us) would have direct contact (maybe a handshake, a hug, and a kiss) with every other human on earth, all in the same day!

What would happen with each of these extremes, given current COVID-19 infections?

Case #1: with maximum social distancing, pandemic over in 6 weeks, with 10 000 to 100 000 deaths

In case #1, there would be no spreading.  Of the current 10 million or so people who might carry the virus at the beginning of the 6 week period, perhaps  0.1 - 1%  would die, which means 10 000 - 100 000 deaths.  This is the lowest possible number of deaths from the pandemic, unless a cure is found in the next 6 weeks. 

After that 4-6 week period, the virus would be gone, and COVID-19 would no longer exist in the human population, unless it was introduced again from animals.  The pandemic would be permanently, completely over.  A variety of other human diseases would probably be greatly reduced as well.

Case #2: with maximum social contact, pandemic over in 6 weeks, with up to 160 million deaths

In case #2, everyone would contract the virus.  The death rate would be higher than case #1 since health care resources would be massively overwhelmed.  Let's say a  2 % death rate, which means 160 million deaths, all over a 1-2 month period,  which would basically be the worst devastation in human history.   After this point, the virus would also most likely be done, people would probably be immune, and the pandemic would be over.

We can see by comparing case #1 and case #2, which differ only in how much social distancing took place, that social distancing has a clear , huge effect on mortality.  The maximum effect of social distancing alone would be to reduce deaths about a thousand-fold and to put an end to the pandemic.

Conclusion: By social distancing alone, it is possible to theoretically end the pandemic in 6 weeks, with a minimum of fatalities.  But of course such a plan would prevent most normal activities in society for over a month.

Thought experiment #2: the two hypothetical extremes of testing

The two extremes of testing are as follows:

case 3) Every person could instantaneously know if they were a viral carrier, at every moment.  An imaginary device to accomplish this would, for example, be an electronic monitor that everyone would wear, that would instantaneously light up if a virus was detected in someone's exhaled breath.
A watered-down version of this, which is theoretically possible at present (if not feasible at scale yet), would be to have every person in the population tested every single day, with results available in minutes.

case 4) No testing at all would take place.  This is not far from what is really happening in some places.

What could happen in each of these cases?

Case #3: with maximum testing, pandemic over in 6 weeks, 10 000 to 100 000 deaths, with minimal disruption to daily quality of life

Every person with virus detected could promptly isolate, eliminating any chance of spread.  Since the tests would be done continuously on all people, there would be no chance for asymptomatic spreading.  The mortality result would be similar to Case #1 above, with the pandemic over in 6 weeks, with under 100 000 deaths.  But unlike Case #1 above, Case #3 would only require a 6-week isolation of the 1% or so of the population which carries the virus.  The other 99% of us would be entirely free to live normally, with no social distancing required.

Case #4: with no testing, pandemic over in years, or never over, with 4 million deaths 
With no testing, we would have gradual spread to the entire population, occurring over a period of months to years.  It would continue spreading because of asymptomatic transmission.  We could assume a lower death rate than case #2, since the health system would be less overwhelmed, and there would also be more time to develop better treatments.  So let us assume a 0.05% death rate overall.  This means about 4 million deaths.

Conclusion: testing, done as frequently as possible, and of as many people in the population as possible, has a clear, huge effect on mortality, on the duration of the pandemic, and on preserving a more normal quality of life.  Testing and isolating alone could also end the pandemic in 6 weeks, with a minimum of life or economic disruption.

What conclusions can we take from these hypothetical thought-experiments?

Social distancing obviously works.  The logic above shows it.   It needs to be extremely rigorous and disciplined, with everyone participating, in order for it to help best.  If some people are not participating, the virus still has a chance to spread.

There are actions that will increase the effectiveness of social distancing, to “magnify”  it if you will.  These actions include widespread face mask usage, plastic barriers, hand-washing, and frequent disinfection.

Frequent testing also works.  Experiments are not necessary to prove this.  The logic outlined above proves it!  With a maximum of testing, the pandemic could be over in 6 weeks, but unlike the social distancing technique, it would require much less disruption to the population, to lifestyle, and to the economy.

In practice, we are imperfect people, our governments are very imperfect, and also the technology required to put these two types of ideas into place are limited.  It takes time and money to manufacture test kits and to develop the infrastructure to distribute or administer them, and to arrange to isolate every positive.

What can we do in the meantime?  Individuals do not have the power to make more frequent testing happen.  But individuals can adhere to social distancing with as much discipline as possible.  This clearly will help.

What can businesses, schools, churches, and other group organizations do?  They can enforce rules of social distancing for their employees, students, or members.  They can sponsor campaigns to persuade others to follow the rules.  They could use their political influence to urge governments to do the same.

Industries could participate, to the best of their ability, in the mass-manufacture of testing kits if possible, and of other useful technology, such as masks.

Governments have some power to enforce social distancing, and in my opinion they should use it, if they want the pandemic to end sooner, to save more lives, and to get the economy going sooner.
Governments and industry also have the power to maximize the production and deployment of tests.  If the number of tests could be increased 10-fold, or 100-fold, or 1000-fold compared to where they are now, this will put a very powerful brake on the pandemic, and give us the chance to eliminate the virus entirely, with the smallest possible disruption to our lives.    Really, I don't understand what they have been waiting for; every day of not maximizing test kit production is a day of needlessly careening towards greater and greater catastrophe and death.

If both distancing and testing are done in a non-committal, half-hearted, slipshod manner, then there will be probably some reduction in case numbers, a "bending of the curve," but the pandemic will drag on possibly for years, or until a vaccine is found to work, is mass-produced, and given to the entire population.

There are, of course, other things to work on towards solving the COVID-19 problem, especially vaccine development.  But this is likely to take quite a long time.  It would be unprecedented for a new effective vaccine to be available within a year.  But then, I am always amazed with what human ingenuity can accomplish, so I wouldn't be surprised if a good vaccine is indeed developed in record time.

There is also the hope that new, more effective drug treatments can be found.  This research is just beginning to hint at some more effective developments.  I wouldn't be surprised if much better drug treatments will come along in the next months as well.

Sunday, April 5, 2020

COVID-19 update April 5 2020

The main advice about COVID-19 is just the same as before:  very strict social distancing (stay at least 2 metres, or 6 feet away from other people at all times), stay at home as much as possible,  wash your hands very thoroughly after touching anything that someone else might have touched, and do not touch your face unless your hands have been very carefully washed.

Please keep in mind that the 2 metre or 6 foot social distancing guideline is an arbitrary recommendation.  It would clearly be more effective to have 4 metres of social distancing!  The 2 metre recommendation is a starting point, but it would be best of all to avoid all crowds entirely, and even to avoid places which have been crowded in the previous hours (especially indoor places). 

These measures alone are helping to contain the spread of the disease, but we need to keep this up for many more weeks or months.

It has become clear (unsurprisingly) that disease spread can be significantly reduced if as many people as possible are wearing masks, especially in crowded places such as grocery stores or public transit.  Masks probably are most effective to prevent a person with COVID, including the many people without active symptoms, from spreading it.  Therefore, mask usage, if it is to be optimally effective, has to be used on a massive scale.

However, we have a terrible shortage of medical masks.  So it will be necessary to make home-made masks, or use scarves, until we have an abundant supply for the public of medical masks.  Medical masks need to be prioritized for medical workers, community workers, transit drivers, and grocery store staff.

It is valuable to look closely at what China, South Korea, and Taiwan have done to get their COVID-19 infections under good control.  We should be well-informed about their strategies, and copy.  Generally, my impression is that their strategies are similar to what we are doing here, but much more strict and enforced.

One of the issues of the week has to do with hydroxychloroquine and azithromycin as possible treatments for COVID.  The only evidence for these comes from so-called "in vitro" experiments; there is not yet any supportive evidence for their use in people with COVID.  But it is still important to study the question, which has to be done in a randomized controlled fashion.  Results of this research will take weeks.   I am neutral on this question, as we have no good evidence to guide us one way or the other on it, except for a recent negative study showing that it is not useful in severely ill patients.  It remains to be studied whether they could be effective if given early in the disease process, or prophylactically.   It is very clear that these drugs should not be endorsed, as they have potentially dangerous side effects.  And the public focus on this issue in the U.S. may distract people from focusing on what actually IS proven to help, which is social distancing, staying home, hand washing, and mask use.

I have thought of a modification of my "COVID hotel" idea, (see https://garthkroeker.blogspot.com/2020/03/covid-19-management-brainstorm-ideas.html) which is much less controversial.  It would seek participants for the hotel from a cohort of people working in high-risk zones, such as hospital staff, emergency response workers, and grocery clerks.  A cohort of several thousand such people would be followed closely, with a COVID test being given daily.  There would be no inoculation--each person who ended up with COVID would have acquired it in the course of their work.  Every person with a positive test would be promptly enrolled in the COVID-hotel study.  The advantage of this technique compared to present research studies, is that we could be guaranteed that every participant had become positive within the previous 24 hours, therefore would all be in an equivalently early stage of infection.  I hypothesize that any treatment intervention (such as an antiviral drug) would have the best chance of working if given as early as possible in the infection process.  Since everyone in the study would begin treatment at the exact same stage of infection, it would greatly reduce variability in outcome simply due to giving the drug at a different stage.

Friday, April 3, 2020

Mental Health care during COVID-19

With COVID-19, we are all likely to experience great hardships:  social isolation, cramped living quarters, severe financial problems, daily anxiety about going outside, difficulties with simple activities such as getting groceries or basic supplies, and of course the awful horror when we learn about what is going on elsewhere.  "Elsewhere" for now may be an abstraction about some city far away, but at some point "elsewhere" will get closer to home, to our families, to our loved ones. 

Symptoms of all mental illnesses have a high chance of becoming more severe.  

What can we do?  

I don't have the answers.  I'm scared myself.  

But here are some reminders about the basics: 

1) to the best of your ability, eat well, sleep well, and get some exercise, every day.  Try to have a schedule about doing these things.  It may not be possible to get these things done.  Normal sleep may be impossible due to anxiety.  But try.  Have a schedule.  Do your best.  Avoid things that make you worse emotionally, such as too much caffeine, too much junk food, etc.  

2) Try to focus on something else other than COVID news.  Read.  Study.  Clean.  Play video games.  

3) Have social contact.  This would have to be on the phone, by email, by Skype or FaceTime.  Or you could talk or sing to people who live nearby, as they are doing in Italy.  

4) Plan for what you'd like to do when this is all over.  It could be brief, over months, but maybe this could drag on for a year or more.  Think of the great celebration we will have then.  

COVID update April 3, 2020

As the pandemic progresses, we see more and more abundant evidence that very strict social distancing is effective.

2 metres (or 6 feet) of social distancing means that if both you and a person next to you have your arms extended, stretched out as far as you can reach, you should not be able to touch the other person's fingertips.

As expected, mask use is gaining more clear evidence.  Probably the greatest benefit of wearing a mask is to prevent the mask-wearing COVID-positive person (including the many people who are carrying the virus but not yet showing obvious symptoms) from spreading the virus to others.  Therefore, to be most useful, everybody should be wearing masks, particularly in crowded places such as grocery stores.

I have updated my idea about a voluntary inoculation technique: https://garthkroeker.blogspot.com/2020/03/covid-19-management-brainstorm-ideas.html
The risk of this technique would be that some of the volunteers would face a risk of death or permanent injury.  But the benefit of the technique would be that a cohort of people would leave the technique in a proven immune state; and the technique would allow much more rapid research (done in the most perfectly rigorous blinded randomized-controlled manner) to establish clearly and in the quickest possible way whether proposed antiviral treatments work or not.  I suspect most antiviral treatments would be much more effective if given in the earliest stages of infection, rather than after severe symptoms have developed.  This is true of other antiviral treatments, such as acyclovir for HSV.  This technique would allow a guaranteed method of testing whether such antivirals would make a difference for people guaranteed to be infected but who are in the earliest pre-symptomatic stage.  In getting these answers quickly (saving weeks to months of time), tens of thousands of lives could be saved as we determine much more quickly which treatments actually work and which do not.  Not only could it identify effect sizes of effective treatments rapidly, it could also give us the information which would lead us to stop  offering putative treatments that may actually be harmful.

Meanwhile, I continue my advice to keep up social distancing.  Wash your hands very thoroughly and frequently, with an extra time whenever you have touched anything that anyone else might have touched.  Learn about good hand-washing technique.

Mask use has strong evidence.  But there is a shortage of masks for those who need them most.  So people will have to improvise their own home-made masks.

I encourage keeping some disinfecting cloths with you.  Clorox wipes are in short supply, but you can make your own by cutting up some old clothes into rags, and storing them in a glass jar containing a strong antiseptic such as Mr. Clean.

Avoid going out unless it is absolutely necessary.  I do consider daily exercise necessary, but if you do this, choose a time when fewest people are around, and a place where there is the least crowding.  I suggest sunrise or midnight.  Of course, be mindful about other safety risks.