4 ms·

I don’t know if I would advocate for “excessive” endoscopies. You’re right: there’s a not insignificant chance for injury or death and I can imagine an situatio

I don’t know if I would advocate for “excessive” endoscopies. You’re right: there’s a not insignificant chance for injury or death and I can imagine an situation where the risk goes up due to the staff being overworked. However, a non-invasive scan (ultrasound, CT) still has a decent chance of catching prostate cancer and hernias, and as far as I’m aware they carry zero risk of injury or death.

vidarh 4y ago
CT scans are not risk free. They're x-rays and while again the individual risk is tiny, doing a large number of them over a large population would be expected to increase incidence of cancer [1] (in fact more so than I thought). External ultrasound (ultrasounds can also be done endoscopically) itself I think is risk free, but inducing anxiety in patients or exposing patients to a healthcare facility is categorically not risk free even though the risk is very small for each individual patient. The problem is not that the risk is high for individual screening events, but that even a one in a million even will happen regularly once you start regularly screening a multi-million person population. There is no such thing as a risk free event once the scale is large enough, so the question becomes whether the risk is low enough relative to the potential benefit, and then you need to consider that often a true positive is rare, and making a difference to the outcome of a true positive is even rarer, so depending on what you're looking for even a one in a million adverse outcome might negate the benefit or worse. EDIT: To add one more point: If you do external ultrasounds and find a potential cancer, you will be prescribing additional tests. Any false positives from the ultrasound will thus end up contributing to excess further testing, and you need to count the harm from that as well. A 1% false positive rate coupled with a 1:10k cancer risk from a follow up CT scan or a (I don't know what the real rate is for perforation) 1:10k risk of perforation with an endoscopy and you have a one in a million severe adverse effect. Do it enough and you'll have deaths even when the starting point is something as innocuous as an external ultrasound. That doesn't mean it can't be worth it. But it does mean you need a risk analysis before any largescale screening effort. [1] https://www.cancer.gov/about-cancer/diagnosis-staging/ct-scans-fact-sheet https://www.cancer.gov/about-cancer/diagnosis-staging/ct-sca... > Individuals who have had multiple CT scans before the age of 15 were found to have an increased risk of developing leukemia, brain tumors (6), and other cancers (7) in the decade following their first scan. However, the lifetime risk of cancer from a single CT scan was small—about one case of cancer for every 10,000 scans performed on children.

vidarh 4y ago

CT scans are not risk free. They're x-rays and while again the individual risk is tiny, doing a large number of them over a large population would be expected to increase incidence of cancer [1] (in fact more so than I thought). External ultrasound (ultrasounds can also be done endoscopically) itself I think is risk free, but inducing anxiety in patients or exposing patients to a healthcare facility is categorically not risk free even though the risk is very small for each individual patient. The problem is not that the risk is high for individual screening events, but that even a one in a million even will happen regularly once you start regularly screening a multi-million person population. There is no such thing as a risk free event once the scale is large enough, so the question becomes whether the risk is low enough relative to the potential benefit, and then you need to consider that often a true positive is rare, and making a difference to the outcome of a true positive is even rarer, so depending on what you're looking for even a one in a million adverse outcome might negate the benefit or worse. EDIT: To add one more point: If you do external ultrasounds and find a potential cancer, you will be prescribing additional tests. Any false positives from the ultrasound will thus end up contributing to excess further testing, and you need to count the harm from that as well. A 1% false positive rate coupled with a 1:10k cancer risk from a follow up CT scan or a (I don't know what the real rate is for perforation) 1:10k risk of perforation with an endoscopy and you have a one in a million severe adverse effect. Do it enough and you'll have deaths even when the starting point is something as innocuous as an external ultrasound. That doesn't mean it can't be worth it. But it does mean you need a risk analysis before any largescale screening effort. [1] https://www.cancer.gov/about-cancer/diagnosis-staging/ct-scans-fact-sheet https://www.cancer.gov/about-cancer/diagnosis-staging/ct-sca... > Individuals who have had multiple CT scans before the age of 15 were found to have an increased risk of developing leukemia, brain tumors (6), and other cancers (7) in the decade following their first scan. However, the lifetime risk of cancer from a single CT scan was small—about one case of cancer for every 10,000 scans performed on children.