10 ms·

We don’t advocate less frequent scans, we advocate targeted scans. Because the probability of a positive result being a false positive depends heavily on the po

We don’t advocate less frequent scans, we advocate targeted scans. Because the probability of a positive result being a false positive depends heavily on the population. In a population with a high baseline frequency, the probability of a positive being false is relatively low; in a population with a low baseline frequency, the likelihood of a positive being false is relatively high. So, you don’t mammogram every person with a breast. You mammogram people with advanced age, genetic predisposition, etc. so as to select for a population with a reasonable baseline frequency. Various professional bodies and the USPTF put a lot of effort into determining what the optimal screening population is. Clinical decision rules are an extremely active part of medical research. Trying to figure out a reasonable predictive model to say “definitely follow up on this” or “definitely don’t” is a huge field in medicine. For instance, in patients ≥35 years old with incidental pulmonary nodules on CT imaging, we have the Fleischner Guidelines for when and which follow-up is appropriate. But it required a number of prospective external validation studies in order to properly validate it, and it’s for one super specific population: under-35 incidental pulmonary nodule on non-cancer-screening CT. So, you can imagine how much work there is to be done for the other 10,000 kinds of incidentalomas.

jcims 7y ago
Sitting in the oncology dept right now with my wife who’s gaving complications from a tumor. I’d just be happy with peer reviews of radiology reports so fuckups don’t cost us three months of potential treatment. I’m sitting bedside wading through pull requests for software installation scripts. How is it the opinions of folks on my team for a bullshit process get more scrutiny than a potentially life-altering assessment that requires expertise, a keen eye and sharp mind every time?
- jmhmd 7y ago
  Radiologist here. Sorry to hear about about your wife's complications. Most radiology departments do participate in a peer review process as part of internal quality assurance. Not every report is necessarily peer-reviewed, largely due to time constraints (radiologists can read hundreds of mammograms in a day), and not all modalities are required to participate (I believe mammography is optional).
  - jcims 7y ago
    Thank you. I think it would be an extremely difficult job, particularly with a high throughput demands. This series was abdominal and i guess i would expect to see some annotation indicating it was reviewed. In this case we had a scan in Nov. that was marked clear. Scan in Feb that had an unsized spot noted as ‘possibly metastatic’ with a note that ‘in retrospect this focus was present in previous exam’. Oncologist explains lack of measurement as being too small to precisely ascertain. Then two weeks ago we have a scan report indicating (among other new disease) a 4cm mass that was ‘previously 2cm.’ People are guaranteed to make mistakes, and my issue is with the process...not the personnel.
- tejtm 7y ago
  I've been there and recently, I hope you come through at least as well as we have. My understanding is at minimum several radiologists lay eyes on before you hear anything from any of them. P.S. My wife wife says she wishes you and your wife all the best.
  - jcims 7y ago
    Thank you so much for the well wishes, and please extend our gratitude to your better half as well. I never appreciated the role that the support of others plays in the healing process untill I saw it first hand. It gives my beautiful bride a source of strength and confidence that keeps her stress that much lower and her outlook that much brighter.
MegaButts 7y ago
But doesn't this approach make it nigh impossible to catch people that don't fit the mold? It almost seems like it becomes a tautology, by not capturing the diseases in people you don't think have them, and only looking in people that you do think have them. And the only way to change the mold is for enough people to likely die that you reevaluate the model. I am not a doctor, but I cannot fathom why a doctor would ever advocate against more data. Even if that doctor chooses to ignore it, at least let the patient utilize it as he sees fit. As someone who has regularly had to argue with doctors to get a test done, it is incredibly frustrating.
- arkades 7y ago
  Well, that’s part of why there’s constant research into what risk factors / predictive factors are. These aren’t mutually exclusive activities. “Data” implies something neutral. Nothing about lab tests is neutral. Without contextual information and studies on how to -interpret- a finding, it’s just potentially terrifying noise. And terror usually results in action. Poorly informed action is often harmful. So... we are trying to prevent harm to our patients. We are earnestly working on all fronts to build the studies to better interpret these findings. But we just aren’t there yet.
  - MegaButts 7y ago
    I understand it is not a black-and-white situation, and that data is obviously not perfect. And I certainly am not advocating that doctors should order a gamut of tests unnecessarily. But if there is any doubt, how likely is the added data to harm more than help? And I firmly believe the doctor should not fight the patient on a test unless there is a strong reason not to (apart from an obvious medical disorder such as Munchausen syndrome it is hard for me to think of a reason). If the added data is noise, it can easily be ignored. If it's not noise, then you're lucky to have it. And figuring out whether or not it is noise is important, but you can't do that without the data. But again, I am not a doctor, and how much bandwidth they have and where their priorities lie is not something I intimately understand. However something that has become blindingly obvious to me is that most doctors do not have a firm grasp of statistics, and will advocate for new drugs when the actual test results are borderline statistically insignificant and easily explained away by confounding factors (most obviously the placebo effect). Sadly not all trials are double-blind, something else I do not understand.

jcims 7y ago

Sitting in the oncology dept right now with my wife who’s gaving complications from a tumor. I’d just be happy with peer reviews of radiology reports so fuckups don’t cost us three months of potential treatment. I’m sitting bedside wading through pull requests for software installation scripts. How is it the opinions of folks on my team for a bullshit process get more scrutiny than a potentially life-altering assessment that requires expertise, a keen eye and sharp mind every time?

jmhmd 7y ago
Radiologist here. Sorry to hear about about your wife's complications. Most radiology departments do participate in a peer review process as part of internal quality assurance. Not every report is necessarily peer-reviewed, largely due to time constraints (radiologists can read hundreds of mammograms in a day), and not all modalities are required to participate (I believe mammography is optional).
- jcims 7y ago
  Thank you. I think it would be an extremely difficult job, particularly with a high throughput demands. This series was abdominal and i guess i would expect to see some annotation indicating it was reviewed. In this case we had a scan in Nov. that was marked clear. Scan in Feb that had an unsized spot noted as ‘possibly metastatic’ with a note that ‘in retrospect this focus was present in previous exam’. Oncologist explains lack of measurement as being too small to precisely ascertain. Then two weeks ago we have a scan report indicating (among other new disease) a 4cm mass that was ‘previously 2cm.’ People are guaranteed to make mistakes, and my issue is with the process...not the personnel.
tejtm 7y ago
I've been there and recently, I hope you come through at least as well as we have. My understanding is at minimum several radiologists lay eyes on before you hear anything from any of them. P.S. My wife wife says she wishes you and your wife all the best.
- jcims 7y ago
  Thank you so much for the well wishes, and please extend our gratitude to your better half as well. I never appreciated the role that the support of others plays in the healing process untill I saw it first hand. It gives my beautiful bride a source of strength and confidence that keeps her stress that much lower and her outlook that much brighter.

MegaButts 7y ago

But doesn't this approach make it nigh impossible to catch people that don't fit the mold? It almost seems like it becomes a tautology, by not capturing the diseases in people you don't think have them, and only looking in people that you do think have them. And the only way to change the mold is for enough people to likely die that you reevaluate the model. I am not a doctor, but I cannot fathom why a doctor would ever advocate against more data. Even if that doctor chooses to ignore it, at least let the patient utilize it as he sees fit. As someone who has regularly had to argue with doctors to get a test done, it is incredibly frustrating.

arkades 7y ago
Well, that’s part of why there’s constant research into what risk factors / predictive factors are. These aren’t mutually exclusive activities. “Data” implies something neutral. Nothing about lab tests is neutral. Without contextual information and studies on how to -interpret- a finding, it’s just potentially terrifying noise. And terror usually results in action. Poorly informed action is often harmful. So... we are trying to prevent harm to our patients. We are earnestly working on all fronts to build the studies to better interpret these findings. But we just aren’t there yet.
- MegaButts 7y ago
  I understand it is not a black-and-white situation, and that data is obviously not perfect. And I certainly am not advocating that doctors should order a gamut of tests unnecessarily. But if there is any doubt, how likely is the added data to harm more than help? And I firmly believe the doctor should not fight the patient on a test unless there is a strong reason not to (apart from an obvious medical disorder such as Munchausen syndrome it is hard for me to think of a reason). If the added data is noise, it can easily be ignored. If it's not noise, then you're lucky to have it. And figuring out whether or not it is noise is important, but you can't do that without the data. But again, I am not a doctor, and how much bandwidth they have and where their priorities lie is not something I intimately understand. However something that has become blindingly obvious to me is that most doctors do not have a firm grasp of statistics, and will advocate for new drugs when the actual test results are borderline statistically insignificant and easily explained away by confounding factors (most obviously the placebo effect). Sadly not all trials are double-blind, something else I do not understand.