Hacker News Reader

Comment by fpgaminer | Hacker News Reader

> because that means it's less fatal than we thought

Don't we already have solid numbers on the fatality rate because of the Diamond Princess? A change in estimated R0 wouldn't affect that.

View on HN

Diamond princess was tested early and often and therefore able to get immediate quality care before medical systems were overwhelmed. This gives something like the ideal minimum fatality rate if, for the most part, everything goes right with detection & treatment.

Out in the wild, this is very much not the case. Testing it still thin on the ground in many locales and the pressure exerted on the medical infrastructure is not evenly distributed, making levels of care vastly different.

Think of it like a highly treatable form of cancer: If everything goes right and it's caught in early stage 1, fatalities rates are much lower than when it's only detected after reaching stage 4 and fatality rates are much higher.

Diamond Princess, for distinct demographic group only, represents detection at Stage 1.

Diamond princess is a non-stochastic sample, with all its attendant biases.

What does that mean?

People on cruise ships are usually not a good sample of the general population, for example, the mean age is quite high.

But it is also a sample with few in the sickest bracket, who are a disproportionate fraction of deaths.

And the number of deaths is sufficiently small that it is consistent with a wide range of death rates.

Another way to put it is that the study is enumerative and not analytic. Unfortunately, just about every study being done on COVID is enumerative.

https://en.m.wikipedia.org/wiki/Analytic_and_enumerative_sta...

"Diamond princess is a non-stochastic sample, with all its attendant biases."

But isn't it a non-stochastic sample in the right direction ? Which is to say, the demographics of budget cruise line passengers are almost a worst-case. They represent the most susceptible cohort.

What we can infer from Diamond Princess is that the general population will, all else being equal, fare better statistically.

Yes, but I was responding to a claim that we already had "solid numbers on the fatality rate". They're far from solid. We have a small sample that gives us an idea of the CFR, for that demographic, but this tells us very little about global IFR.

The town of Vò, 3300 tested repeatedly, 89 tested positive, 1 death.

If fatality rate is 0.1%, there was only a 10% chance of 1 death i.e. it is very likely death rate is higher than 0.1%. Also the Diamond Princess numbers are relevant, after adjusting for age spread in a normal population, it is a lot more than 0.1%.

How do you get 10%? On avg you expect 3.3 people to die if IFR is 0.1%, so it shouldn’t be as low as 10% likely to get 1.

IFR relates death to total infected, not total population.

Iceland has the most comprehensive testing, and their fatality rate is around 0.3%.

There are a couple of reasons for that, most likely. First, only 4.5% of the known cases in Iceland are over 70 years old. In Italy, around 16% of the population is 70+, so given that this virus has much higher death rates for the elderly, we would expect a much lower death rate than Italy. Second, there are still 11 people in intensive care (compared to six deaths). I'm not sure what the mortality rates are for patients that require intensive care, but I assume they would be much worse than average. I think I remember seeing about 20-30% mortality for ICU patients from a study in Italy. Finally, the majority of cases in Iceland are still ongoing, whereas many villages in Northern Italy have gotten through the worst of it, with fairly few cases unresolved. I bet that the age adjusted fatality rate in Iceland will end up being fairly similar to Italy.

I agree. So, the scalar fatality rate should be adjusted to the normal population distribution.

That's a crowd that skewed older in age, amongst other issues.

You can adjust for age just fine as every country has different demographics. The real issue is the crew and passengers where significantly healthier than the demographics suggest.

Aka people undergoing chemo are less likely to go an a cruse.

I've heard tale that people have opted to be permanent cruise ship residents over living in assisted living facilities.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC526150/ https://www.cnbc.com/2016/07/26/ahoy-matey-more-folks-retiri...

Permanent is rather misleading in that context. These these people don’t have major mental or physical impairments yet. Their old enough to retire, but heathy enough to enjoy it.

That's not obvious to me. You can imagine people might take a cruise over a walking tour of Tuscany because the cruise is much more accommodating of physical disability, you can get around with a wheelchair, there's lots of staff to help, etc.

You can, but the cruise will not let you on once you reach a certain level of disability. Wheelchair is no problem, but if you can't get yourself out of bed into the wheelchair they will kick you off. Similar for other disabilities, minor cases are fine, but if you can't mostly take care of yourself you are off.

A cruise is one of the cheaper assisted living arrangements if you qualify, (but governments will not subsidize your cruise while if you need assisted living they will). Part of it is discounts for inside cabins, part of it is they know you are there and will give various jobs when they need help which helps pay for your cruise.

Reply on news.ycombinator.com