3 ms·

And that - no matter who good the test, and no matter how early - leads to a decrease in positive patient outcomes. You keep writing comments in absolute terms

And that - no matter who good the test, and no matter how early - leads to a decrease in positive patient outcomes. You keep writing comments in absolute terms and talking about evidence, but how do you reconcile your position with the results of successful screening programmes like cervical smear testing? Detecting and treating high risk HPV before it causes changes that can turn into cervical cancer has dramatically reduced the harm caused by cervical cancer itself at a population level. Routine screening of this type isn't normally recommended for young women, but it becomes increasingly effective with age and screening programmes operate accordingly.

jacquesm 5y ago
Yes, but that's one specific cancer. There are a few others for which this is the case and absent genetic data a few that are borderline cases (notably: breast cancer, where the presence or absence of a mutation is a very relevant bit of data).
- Silhouette 5y ago
  So you do agree that evidence-based screening programmes can be effective then? In that case, I'm sorry but I don't quite understand the point you're trying to make here.
  - jacquesm 5y ago
    Yes, they can, but not in a blanket fashion where a test with a relatively high false positive rate and a relatively low sensitivity (between 18 and 50% for this particular test) is released without patient outcomes as the main driver of whether or not to apply the test absent further symptoms. Whether this test is one that can serve in that particular role is definitely not something that has already been determined and those advocating for such are ignoring a mountain of established science and are simply jumping the gun. Policy is set by the overall effect of application, which can be quite different than applying that same tool in an individual setting. This whole thread started with "This is one of those medical revolutions that I am waiting dearly for. Facilities that are not hospitals(to avoid the risk of occupying medical devices that sick people need) built to _regulary_ check up otherwise healthy people for preventive care." And that is not something you do without taking into account the downsides. Whether this is revolutionary or not remains to be seen, it definitely is a useful test based on what I've read about it so far.
    - Silhouette 5y ago
      Well, yes, it's only worth running a screening programme if you have a usefully accurate test and if you can then make some useful intervention after a positive result. Is anyone here disagreeing with that, though? Maybe we interpreted OP's comment that you quoted differently? I read it as being in favour of preventative medicine as a whole, not necessarily endorsing this specific test at this specific point in time. Maybe I'm also interpreting some of the other comments in this discussion, including yours, differently to how their authors intended them. My concern is that as written they appear to be criticising all use of screening, regardless of its efficacy, which is extremely dangerous.
      - jacquesm 5y ago
        That certainly isn't the goal, it is strictly meant within the context as established by the root comment. To present this at the present time as a revolutionary breakthrough and to suggest using this test in particular for mass screening is not a path that will lead to a good outcome unless a lot more data is gathered to support that position. The people that have built this are at the forefront of this field, I've been following them for quite a while - since the announcement in March last year - it has direct bearing on some other things that I'm involved with and I'm hopeful that it will at first be a useful diagnostic tool and that in a later stage - after the kinks have been worked out and there is sufficient data - that it might help with more than that. Preventative medicine obviously has its place and for selected cancers we are now in a phase where early detection leads to improved outcomes. But we should continue to be weary of overselling this - the same has already happened with other cancer tests. Absent symptoms mass testing has serious risks and these will obviously be taken into account when setting policy, the article is actually reasonably neutral in this respect so I wonder why it leads to an immediate response that is equating this with a medical revolution. It may well be, but there is no evidence right now that this is the case.
    - ggrrhh_ta 5y ago
      Well. With a bad test, what is necessary is to improve the test. The argument "outcomes are worse off with more absent symptoms testing" is really saying that symptoms is more predictive than the test itself: test is positive if [symptoms & positive result] test is positive or neutral if [no symptoms & should have been screened & positive result] and test is negative if [no symptoms & should not have been screened & positive result] (notice that this does not change the outcome to not testing people without symptoms and without another reason to do so). Until the tests/decision protocols were improved to avoid false positive, this third case should be communicated to the person as a negative result of the test (if we are convinced that the overall outcome is better off if the test should not have been administered at all), but I would find that unethical and dehumanizing and I understand touches on lots of ethical issues: the stress of waiting for a result, the liability of not being an actual false positive, etc. So, I understand, that given the current state of the testing, the decision is to restrict when to do it.

jacquesm 5y ago

Yes, but that's one specific cancer. There are a few others for which this is the case and absent genetic data a few that are borderline cases (notably: breast cancer, where the presence or absence of a mutation is a very relevant bit of data).

Silhouette 5y ago
So you do agree that evidence-based screening programmes can be effective then? In that case, I'm sorry but I don't quite understand the point you're trying to make here.
- jacquesm 5y ago
  Yes, they can, but not in a blanket fashion where a test with a relatively high false positive rate and a relatively low sensitivity (between 18 and 50% for this particular test) is released without patient outcomes as the main driver of whether or not to apply the test absent further symptoms. Whether this test is one that can serve in that particular role is definitely not something that has already been determined and those advocating for such are ignoring a mountain of established science and are simply jumping the gun. Policy is set by the overall effect of application, which can be quite different than applying that same tool in an individual setting. This whole thread started with "This is one of those medical revolutions that I am waiting dearly for. Facilities that are not hospitals(to avoid the risk of occupying medical devices that sick people need) built to _regulary_ check up otherwise healthy people for preventive care." And that is not something you do without taking into account the downsides. Whether this is revolutionary or not remains to be seen, it definitely is a useful test based on what I've read about it so far.
  - Silhouette 5y ago
    Well, yes, it's only worth running a screening programme if you have a usefully accurate test and if you can then make some useful intervention after a positive result. Is anyone here disagreeing with that, though? Maybe we interpreted OP's comment that you quoted differently? I read it as being in favour of preventative medicine as a whole, not necessarily endorsing this specific test at this specific point in time. Maybe I'm also interpreting some of the other comments in this discussion, including yours, differently to how their authors intended them. My concern is that as written they appear to be criticising all use of screening, regardless of its efficacy, which is extremely dangerous.
    - jacquesm 5y ago
      That certainly isn't the goal, it is strictly meant within the context as established by the root comment. To present this at the present time as a revolutionary breakthrough and to suggest using this test in particular for mass screening is not a path that will lead to a good outcome unless a lot more data is gathered to support that position. The people that have built this are at the forefront of this field, I've been following them for quite a while - since the announcement in March last year - it has direct bearing on some other things that I'm involved with and I'm hopeful that it will at first be a useful diagnostic tool and that in a later stage - after the kinks have been worked out and there is sufficient data - that it might help with more than that. Preventative medicine obviously has its place and for selected cancers we are now in a phase where early detection leads to improved outcomes. But we should continue to be weary of overselling this - the same has already happened with other cancer tests. Absent symptoms mass testing has serious risks and these will obviously be taken into account when setting policy, the article is actually reasonably neutral in this respect so I wonder why it leads to an immediate response that is equating this with a medical revolution. It may well be, but there is no evidence right now that this is the case.
  - ggrrhh_ta 5y ago
    Well. With a bad test, what is necessary is to improve the test. The argument "outcomes are worse off with more absent symptoms testing" is really saying that symptoms is more predictive than the test itself: test is positive if [symptoms & positive result] test is positive or neutral if [no symptoms & should have been screened & positive result] and test is negative if [no symptoms & should not have been screened & positive result] (notice that this does not change the outcome to not testing people without symptoms and without another reason to do so). Until the tests/decision protocols were improved to avoid false positive, this third case should be communicated to the person as a negative result of the test (if we are convinced that the overall outcome is better off if the test should not have been administered at all), but I would find that unethical and dehumanizing and I understand touches on lots of ethical issues: the stress of waiting for a result, the liability of not being an actual false positive, etc. So, I understand, that given the current state of the testing, the decision is to restrict when to do it.