POLL IS OVER! Please Do Not Vote.

amother

Sun, Nov 07 2021, 11:49 am

amother [ Brunette ] wrote:

No, because the CDC, unlike you, knows how to conduct a study.

The CDC tested for vaccine efficacy in several trials and then reported rates that did not hold up in the real world.

Vaccine effectiveness rapidly declined with time and initial numbers released by the CDC had to be adjusted.

So vaccine effectiveness rates in the real world is calculated based on a similar methodology to the one being used in this poll. Except it's not being done over in anonymous unverified fashion, as in this poll. I mean, this poll is obviously unreliable. This data is completely unverified. Still find it interesting.

challahchallah

Sun, Nov 07 2021, 12:59 pm

amother [ OP ] wrote:

No. In an anonymous, unverified, uncontrolled way, this poll tells you how likely someone (within the imamother population) who’s never had Covid is to choose to get the vaccine. To be able to see how effective the vaccine is, you have to compare the chance of getting Covid with and without the vaccine.

amother

Sun, Nov 07 2021, 1:06 pm

challahchallah wrote:

Right. This poll is anonymous and unverified. As I said multiple times.

In terms of being controlled, what does CDC control for, outside of their clinical trials? How do they collect real world data?

This poll compares vaccinated + never caught covid to unvaccinated + never caught covid. It's biggest flaw is that we have no idea how many vaccinated posters and how many unvaccinated posters are on this site, and therefore have no idea what percentage of each group caught covid. That is the biggest flaw of this poll. (And it's a pretty big one.) We are only comparing covid rates of the two groups and not how these percentages hold up against the totals of these groups. If one group is significantly larger than the other, that skews the whole poll.

challahchallah

Sun, Nov 07 2021, 1:28 pm

amother [ OP ] wrote:

Right, as you said “ This poll compares vaccinated + never caught covid to unvaccinated + never caught covid.” That comparison tells you within the population of people who have never had Covid, how likely are they to vaccinate.

To figure out the efficacy of the vaccine, you need to take two populations of people that are similar in all characteristics other than one population is vaccinated and the other has not, and compare their rates of catching Covid.

amother

Sun, Nov 07 2021, 1:32 pm

challahchallah wrote:

Interesting, you could make that case that this poll indicates how likely the "not yet infected" population is to vaccinate. But, if we were controlling for group size, this poll could also be informative about how well the vaccine prevents covid.

As to your second point, does the CDC control for similar characteristics when releasing vaccine data?

challahchallah

Sun, Nov 07 2021, 1:46 pm

amother [ OP ] wrote:

You are correct that this poll indicates the likelihood of the “not yet infected” population to vaccinate (obviously with all the caveats we agreed on above that this is the imamother population which is not representative of America broadly). To know how well the vaccine prevents Covid, you need to know how likely getting Covid is with and without the vaccine—there’s just no information you can draw about efficacy without rates of infection. In fact, one reason that studies on the vaccine take time is that you have to wait for enough people to get the disease in order to have statistical power. If you exclude anyone who’s gotten Covid, you have no information on its prevalence.

amother [ OP ] wrote:

As to your second point, does the CDC control for similar characteristics when releasing vaccine data?

Yes, when looking at vaccine efficacy, the CDC looks at the chance of catching Covid (or being hospitalized, or dying, or whatever particular outcome is for that data set) in the unvaccinated population and compares that to the chance in the vaccinated population. How they match up those two populations is what makes good study design hard.

amother

Sun, Nov 07 2021, 1:53 pm

challahchallah wrote:

Leaving aside what you put in the parentheses for a moment (we can get back to that), how is what you describe any different than what this poll is doing? (Aside from the obvious flaws a completely unverified poll like this has- I mean, this poll obviously has zero scientific value- though like I said earlier, it's interesting that it does seem to match up to real world data). When you say "match up these two populations" what specifically do you refer to?

challahchallah

Sun, Nov 07 2021, 2:01 pm

amother [ OP ] wrote:

This poll is comparing an unvaccinated and vaccinated group, while controlling for never having gotten Covid. That tells you how likely vaccination is in the population of people who have never had Covid.

For efficacy calculations, the key outcome is chance of catching Covid with the vaccine compared to chance of catching Covid without the vaccine. In this poll, we don’t know how likely catching Covid is, because no one who got Covid is included.

When I say matching up populations, what I mean is they try to find a population of people that differs in vaccination status, but is similar in other ways such age, race, etc.

amother

Sun, Nov 07 2021, 2:05 pm

challahchallah wrote:

Right. You are essentially paraphrasing what I pointed out- that we don't know total group sizes of these two groups. If we had total group size data, we would obviously have the data on how many of each of these groups did have covid, because:

Caught Covid - Didn't Catch Covid = Total Group Size.

And according to the Commutative Property of math, the following would also apply:

Total Group Size - Didn't Catch Covid = Caught Covid.

Also, I don't think that populations are matched up that way when real world data on the vaccine is released. Can you share an example?

challahchallah

Sun, Nov 07 2021, 2:14 pm

amother [ OP ] wrote:

Ok, sure. You could have collected total group size and indirectly calculated number of people who caught Covid or just collected that information directly. Either way, you’re missing a critical piece of information to be able to say anything about efficacy.

In terms of an example study that takes into account population parameters when looking at efficacy, I actually don’t think I’ve seen a study that doesn’t. You need to look into the details though, not just read the summary. Here’s a study from the lancet that takes into account “age, s-x, race and ethnicity, previous PCR-positive SARS-CoV-2, previous health-care utilisation (inpatient, outpatient, emergency department, or virtual), body-mass index, acute myocardial infarction, congestive heart failure, cerebrovascular disease, peripheral vascular disease, organ transplant, diabetes, malignancy, renal disease, chronic obstructive pulmonary disease, hypertension, Charlson comorbidity index, influenza vaccination in the year before index date, pneumococcal vaccination in the 5 years before index date, and neighbourhood deprivation index30 to capture differences in neighbourhood level socioeconomic status.”

https://www.thelancet.com/jour.....-6736(21)02183-8/fulltext

Edit—lol, the imamother filter changed s-x to relations. I’ve added the hyphen in to get around the filter for clarity.

Last edited by challahchallah on Sun, Nov 07 2021, 2:25 pm; edited 1 time in total

amother

Sun, Nov 07 2021, 2:19 pm

challahchallah wrote:

Ok, sure. You could have collected total group size and indirectly calculated number of people who caught Covid or just collected that information directly. Either way, you’re missing a critical piece of information to be able to say anything about efficacy.

In terms of an example study that takes into account population parameters when looking at efficacy, I actually don’t think I’ve seen a study that doesn’t. You need to look into the details though, not just read the summary. Here’s a study from the lancet that takes into account “age, relations, race and ethnicity, previous PCR-positive SARS-CoV-2, previous health-care utilisation (inpatient, outpatient, emergency department, or virtual), body-mass index, acute myocardial infarction, congestive heart failure, cerebrovascular disease, peripheral vascular disease, organ transplant, diabetes, malignancy, renal disease, chronic obstructive pulmonary disease, hypertension, Charlson comorbidity index, influenza vaccination in the year before index date, pneumococcal vaccination in the 5 years before index date, and neighbourhood deprivation index30 to capture differences in neighbourhood level socioeconomic status.”

https://www.thelancet.com/jour.....-6736(21)02183-8/fulltext

As I mentioned, controls were used in clinical studies, which drew conclusions that did not hold up in real life due to rapidly declining vaccine effectiveness. That is why they had to adjust their numbers (and recommend boosters, etc).

In terms of real life data, what controls are in place? Is this link referring to a clinical trial or to real world data? Because clinical trial numbers were later adjusted (in a big way). The initial numbers were totally off.

challahchallah

Sun, Nov 07 2021, 2:24 pm

amother [ OP ] wrote:

This is a retrospective study—ie, they did statistical analysis on real world data.

amother

Navy

Sun, Nov 07 2021, 2:45 pm

challahchallah wrote:

This. I do think the results are interesting. My guess is that many people who didn’t contract Covid were cautious about social distancing, masking etc. and so they were more likely to get the vaccine when it became available. Hence more people who never contacted it got the vaccine. But op was polling for entirely different purposes and so she didn’t ask for the info that would help back that up

As for op’s hypothesis it lacks any logic. Thanks to those that helped explain why.