# Tag Info

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### Are Covid-19 vaccines much more deadly than people (and scientists) think?

https://vaers.hhs.gov/data/dataguide.html provides a useful guide for interpreting these data. VAERS deaths are not causal reports, they're just a report where someone (doctor, family member) decided ...
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### BNT162b2 mRNA Covid-19 Vaccine efficacy after 1st dose - explain the statistics

The paper itself describes how this is calculated (see the Methods section), but also see this Q&A at Biology.SE talking more broadly about how efficacy has been defined in these vaccine trials: ...
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### Are Covid-19 vaccines much more deadly than people (and scientists) think?

VAERS has a useful purpose, but in high profile situations such as this the data is often more reflective of data collection issues rather than actual effects of vaccination. In addition to the ...
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### Definition of Prevalence

There are two broad types of prevalence statistics: point prevalence and period prevalence. In both cases, more details need to be specified in order to fully describe the statistic. Point prevalence ...
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### Can superficial injury and exercise elevate AST and LDH levels?

Right now I can address the question on intensity, it seems that pushing things a bit too hard at the gym can cause elevated levels to trigger a detectable increase in AST and LDH, this is also ...
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### How to calculate my "approximate" mortality rate while in ICU?

An individual person does not have a mortality rate: it means the fraction of people out of a group who die over a specific time period. It may seem like your particular chance of dying is that same ...
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### BNT162b2 mRNA Covid-19 Vaccine efficacy after 1st dose - explain the statistics

The formula used for vaccine efficacy is as follows: VE = (ARU - ARV) / ARU (VE: vaccine efficacy, ARU: attack rate in unvaccinated participants, ARV: attack rate in vaccinated participants) This is ...
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### How can someone that is HIV positive not be contagious?

Your back-of-the-envelope calculations seem to be off in estimating the extent of viral load reduction in a treated versus untreated person as well as the risk of transmission for unprotected, ...
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### Why cancer is almost twice as likely in more developed countries compared with less developed countries?

Precisely because developed countries have better air quality, nutrition, sanitation, healthcare, etc. life expectancy is higher and cancer is more likely in these countries. This is because cancer ...
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### How much sleep do adults actually need?

Many well-done newer studies are supporting the theory that quality trumps quantity when it comes to sleep. This excellent article at lifehack.org lists 12 good sources, including “two studies (which)...
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### Human body density statistics

Insulin Resistance, Body Weight, Obesity, Body Composition, and the Menopausal Transition (ScienceDirect, 2000) Because bone and muscle have greater density than water, a person with a larger ...
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### Why has covid-19 death rate reduce over the months?

I haven't seen any evidence that the actual death rate has changed at all. See this Q&A: Does COVID-19 have a case fatality rate of 41%? Is this formula correct? The ratio of "deaths/(recoveries+...
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### What is causing recent increase in R00-R99 deaths?

From the CDC (bold added by me): Provisional estimates by causes of death are subject to some nonrandom sampling error. This is because the delay in receiving the report of a death depends on the ...
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### Are vaccines much more deadly than people (and scientists) think?

we will never know that the vaccine have a probability to kill of ~0.1% Very unlikely given that randomized trials with thousands of participants have been conducted; one meta-analysis pooled 41,141 ...
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### What is the difference between lifetime incidence and cumulative lifetime incidence?

You're thinking of it like "cumulative" + "lifetime incidence"; they're thinking of it as "cumulative incidence" and answering the question "cumulative incidence ...
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### Does this infographic show that masks increased the transmission of COVID-19 in Los Angeles County?

The old saying correlation does not equal causation applies here. In this case the correlation assumed by the question is that masks cause more transmission i.e. Mask mandate -> transmission + ...
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### What are the most age-invariant causes of death?

Nothing is really "invariant", especially if you include the very young and very old. All of the most common causes of death are strongly age dependent: https://www.cdc.gov/injury/wisqars/...
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### As ICD is a global standardization of diseases, is there a global standardization of drugs and if not, why?

I think the closest thing to a "standardization of drugs" are the pharmacopeia: USP European Pharmacopoeia Japanese Pharmacopoeia (just some examples) As you will notice, these are not global ...
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### What are "powered" vs "unpowered" samples in medical studies?

Yes, these are referring to statistical power. Statistical power is the probability of correctly rejecting a null hypothesis given a certain sample size and expected magnitude of effect (i.e., ...
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### Mortality and when a protocol becomes statistically significant

What you are basically asking for is a called a "power analysis" in statistics. If all you have are proportion data (i.e., 99% vs 98% surviving), then for a two-sided test of the null hypothesis that ...
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### How often do ICD codes reflect the actual diagnosis in EHR?

In many cases they do reflect the actual diagnosis. It depends on the disease in question. eMerge network work on validation is for example here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3715338....
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### Awkward: TWINS, but from DIFFERENT DADS? How rare is heteropaternal superfecundation (statistics)?

From this answer on Biology.SE (given and researched by me): Yes, this is possible through something called heteropaternal superfecundation (see below for further explanation). Of all twin births, ...
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### How many people have been instantly killed by smoking?

Short answer: maybe a few, but not instantly. Nicotine poisoning exists but rarely is it fatal. Especially, when it is delivered through smoking. There have been very few incidents of death by ...
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### What are "residual" diseases?

In statistics, the "residual" is what is left over after accounting for the other predictors. I'd suggest that residual is being used here in a similar way. When you classify causes of death, some are ...
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### Is the day-of-week variance in COVID-19 case numbers a well-established phenomenon?

Seasonal and cyclical effects have been studied prior to COVID-19, including day-of-week influences on Emergency Department visit volume. For example, in a study of emergency departments in Western ...
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### Is the day-of-week variance in COVID-19 case numbers a well-established phenomenon?

I haven't seen a lot of research on these intra-weekly (reporting) trends on anything health-related, but there is one paper on such trend on ILI reporting, alas just in the military: In this report, ...

### Why is the reported number of COVID-19 deaths lower on Sundays and Mondays in the US?

While hospitals, clinics, long term care homes and such are of course open and working seven days a week, administrative staff typically only work 5 days a week. So someone comes to work Monday and ...
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