5 ms·

Well, to be fair, the overall risk of death did not seem to be lower for the invited group. The risk was 11.04 vs 11.03 for those with invited colonoscopy, with

Well, to be fair, the overall risk of death did not seem to be lower for the invited group. The risk was 11.04 vs 11.03 for those with invited colonoscopy, with fairly large confidence interval on the control group. But the risk of colon cancer did decrease, with a risk reduction of 18%. Maybe they just didn't track long enough to tease out a bigger risk reduction in overall mortality, or maybe colon cancer is associated with other risk factors for mortality (like age). Why someone would latch onto one result and not the other is probably just "blow the lid off" style reporting.

hef19898 4y ago
Invited or not, if you don't show up to a colonoscopy you don't get one. Which means the study's data on invitations alone cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. Argueing about the randomization of these numbers, and the meta-statistical aspects of that, would be funny if the subject wasn't so serious. It is also the same level of discussion you get from people like JBP, meaning it at least misses the point by a mile.
- thaumasiotes 4y ago
  > Invited or not, if you don't show up to a colonoscopy you don't get one. Which means the study's data on invitations alone cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. This is not an oversight on the part of the study designers. It's called "intention to treat", and studies are done this way to get past the problem that, when you invite a bunch of people to get colonoscopies (or tell them to comply with any medical procedure), the people who go through with it are statistically very different, in all kinds of ways, from the people who don't. This makes the direct comparison of "received treatment" vs "didn't receive treatment" mostly meaningless. You're here advocating for everyone to ignore the study and do a direct comparison of "received treatment" vs "didn't receive treatment". Don't do this.
  - hef19898 4y ago
    I am not doing this, I'm saying the study cannot be used to say colonoscopies don't help.
    - ricardobeat 4y ago
      You just did it again.
      - hef19898 4y ago
        Whatever
    - kgwgk 4y ago
      It cannot be used to say that the help either, but you wrote “Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies.”
      - hef19898 4y ago
        I read it that the invite doesn get you differnces, the colonoscopy itsrlf does. And if that isn't statistically a gold standard, randomization and all tgat, I don't care. What the study says, IMHO, is that invoting people doesn't do any good when people don't show up. Which is an interesting problem, isn't it? Not inviting people might be an option, one that doesn't provide any benefits, except an number of letters not being sent. So I'd say keep the invites, because every single additional person showing up for a screening is a net win. Additional educating efforts will definetly help so, no idea how those can look like so.
        kgwgk 4y ago
        > I read it that the invite doesn get you differnces, the colonoscopy itsrlf does. Differences with what? Not with the counterfactual where those people didn’t get a colonoscopy! (At least as far as I can tell from the results being discussed here.) > every single additional person showing up for a screening is a net win. Maybe. This study doesn’t tell us much about it.
- kgwgk 4y ago
  > cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. Really? You cannot simple compare the outcomes for the people who got an invitation AND got the procedure done with the outcomes for the people who didn’t get an invitation. You need the compare them with the people who didn’t get an invitation BUT would have got the procedure done if they had been invited.
- ricardobeat 4y ago
  You have to look at it from the perspective of medical practice. The hypothesis is that inviting people for a regular check up reduces mortality. If a lot of people don’t take up the offer because the procedure is too invasive, carries some risk, etc. then that is a very relevant variable to take into account. Vs, for example, fecal testing as mentioned in the article. It could have a lower precision, but if uptake is 100% instead of the ~40% for colonoscopy the outcomes could be much better.
  - dis-sys 4y ago
    > then that is a very relevant variable to take into account. but that variable has nothing to do with whether the procedure itself is effective or not.
    - bstpierre 4y ago
      The question in this context is whether it’s an effective public health measure to recommend the procedure to a population: specifically, does it reduce the number of deaths over a given period? Whether it’s effective on an individual basis is a related, but different, different question.
  - darkerside 4y ago
    Behavioral medicine
  - seanmcdirmid 4y ago
    American health insurance really screws the pooch here. If you go for a colonoscopy without a previous fecal testing, it is a diagnostic procedure that is fully covered by your insurance without triggering deductible and copay. However, if you go for fecal testing first and then they find something suspicious that warrants a colonoscopy, it is no linger considered diagnostic (you have a legitimate problem now) and deductible/copays apply. So in practice, doctors will tell you to just get the colonoscopy to save (your own) money.
    - astura 4y ago
- kwhitefoot 4y ago
  > people like JBP, meaning it at least misses the point by a mile. Who?

hef19898 4y ago

Invited or not, if you don't show up to a colonoscopy you don't get one. Which means the study's data on invitations alone cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. Argueing about the randomization of these numbers, and the meta-statistical aspects of that, would be funny if the subject wasn't so serious. It is also the same level of discussion you get from people like JBP, meaning it at least misses the point by a mile.

thaumasiotes 4y ago
> Invited or not, if you don't show up to a colonoscopy you don't get one. Which means the study's data on invitations alone cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. This is not an oversight on the part of the study designers. It's called "intention to treat", and studies are done this way to get past the problem that, when you invite a bunch of people to get colonoscopies (or tell them to comply with any medical procedure), the people who go through with it are statistically very different, in all kinds of ways, from the people who don't. This makes the direct comparison of "received treatment" vs "didn't receive treatment" mostly meaningless. You're here advocating for everyone to ignore the study and do a direct comparison of "received treatment" vs "didn't receive treatment". Don't do this.
- hef19898 4y ago
  I am not doing this, I'm saying the study cannot be used to say colonoscopies don't help.
  - ricardobeat 4y ago
    You just did it again.
    - hef19898 4y ago
      Whatever
  - kgwgk 4y ago
    It cannot be used to say that the help either, but you wrote “Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies.”
    - hef19898 4y ago
      I read it that the invite doesn get you differnces, the colonoscopy itsrlf does. And if that isn't statistically a gold standard, randomization and all tgat, I don't care. What the study says, IMHO, is that invoting people doesn't do any good when people don't show up. Which is an interesting problem, isn't it? Not inviting people might be an option, one that doesn't provide any benefits, except an number of letters not being sent. So I'd say keep the invites, because every single additional person showing up for a screening is a net win. Additional educating efforts will definetly help so, no idea how those can look like so.
      - kgwgk 4y ago
        > I read it that the invite doesn get you differnces, the colonoscopy itsrlf does. Differences with what? Not with the counterfactual where those people didn’t get a colonoscopy! (At least as far as I can tell from the results being discussed here.) > every single additional person showing up for a screening is a net win. Maybe. This study doesn’t tell us much about it.
kgwgk 4y ago
> cannot be used to evaluate the effect of colonoscopies. Seems the study does provide data that allows this so, and shows clear differences in cancer rates and survival rates for those that did get colonoscopies. Really? You cannot simple compare the outcomes for the people who got an invitation AND got the procedure done with the outcomes for the people who didn’t get an invitation. You need the compare them with the people who didn’t get an invitation BUT would have got the procedure done if they had been invited.
ricardobeat 4y ago
You have to look at it from the perspective of medical practice. The hypothesis is that inviting people for a regular check up reduces mortality. If a lot of people don’t take up the offer because the procedure is too invasive, carries some risk, etc. then that is a very relevant variable to take into account. Vs, for example, fecal testing as mentioned in the article. It could have a lower precision, but if uptake is 100% instead of the ~40% for colonoscopy the outcomes could be much better.
- dis-sys 4y ago
  > then that is a very relevant variable to take into account. but that variable has nothing to do with whether the procedure itself is effective or not.
  - bstpierre 4y ago
    The question in this context is whether it’s an effective public health measure to recommend the procedure to a population: specifically, does it reduce the number of deaths over a given period? Whether it’s effective on an individual basis is a related, but different, different question.
- darkerside 4y ago
  Behavioral medicine
- seanmcdirmid 4y ago
  American health insurance really screws the pooch here. If you go for a colonoscopy without a previous fecal testing, it is a diagnostic procedure that is fully covered by your insurance without triggering deductible and copay. However, if you go for fecal testing first and then they find something suspicious that warrants a colonoscopy, it is no linger considered diagnostic (you have a legitimate problem now) and deductible/copays apply. So in practice, doctors will tell you to just get the colonoscopy to save (your own) money.
  - astura 4y ago
kwhitefoot 4y ago
> people like JBP, meaning it at least misses the point by a mile. Who?