Comment by srean
8 days ago
False positives trigger more diagnostics some of which can be harmful, not just psychologically but physiologically as well.
If false positives are ok, why not build a down time detector that rolls a die every 5 mins and alert on hitting a 6.
Additional diagnostics can also be very expensive. Articles like this don’t seem to understand the overall costs to a health system with decisions like these. And that cost eventually does go down into the pockets of patients one way or another.
I think the point of the conversation is that if we take the predatory capitalism out of the way, using MRIs could potentially be a net benefit overall for everyone.
I'd argue that malpractice risk has at least as much negative influence on a physicians judgment.
It's perceived as much less (medico-legally) risky to "do something" (or more often "refer the patient to someone else to do something") than not do something.
OECD data (most recent available, around 2020–2022): MRI units per 100K population: United States ~3.6, Canada ~1.0, United Kingdom ~0.7
I would argue that getting "predatory capitalism" out of the way has sharply curtailed MRI availability where that's been tried. Maybe we should loosen the leash on capitalism a bit to get better care...
> some of which can be harmful,
Like what?
I've seen instances where this is used as an excuse for what is, ostensibly, a trick to dimiss people using something that sounds vaguely professional. Like when doctors say they don't want to do additional x-rays because of the risk of radiation exposure, nvm that if it comes out slightly blurry they'll ask to redo it, or if you're cautious about it initially they'll tell you how it's not big deal and there's more radiation in a cluster of bananas.
Biopsies, radiation from additional scans, surgery, treatment for cancers that would not have developed further.
A lot of potential harms are at a societal level as well—from a public health perspective, if everyone starts having regular MRIs that produce incidental findings which require followup, you’re suddenly tying up lots of resources that would otherwise be available to actually-sick people. A person with symptomatic problems whose treatment is delayed because they can’t get an appointment because the specialists are booked full with incidental findings, that person is indirectly harmed by this.
The radiation from CT scans is not especially concerning at an individual level when there is a compelling reason for it, but, if we’re suddenly doing tons more to investigate incidental MRI findings, there may well be a point where those scans are causing a significant amount of cancer overall—a recent study suggested, I believe, that CT scans may be responsible for 5% of cancers already.
> Like what?
Well, from the original article: "And if someone is over-diagnosed, gets a biopsy and develops an infection, that's a direct harm."
Like when someone has an anaphylactic reaction to the contrast dye for their CT?
Contrast-induced nephropathy?
Gadolinium accumulation in the brain doesn't sound good for you...
Although I think this argument is usually talking about the risks of the resulting procedures (eg an injury or complication related to a biopsy done for a finding on imaging).
I worry particularly about damage to the kidneys, something that you mention in your comments.
It takes a lot to clear the dye.
A colonoscopy has the risk of going very wrong due to a puncture.
Harmful to shareholder value.
Personally I’d rather have cancer checked out rather than have a “wait and die” approach
The United States Preventative Services Task Force[1] reviews studies and meta-studies to make recommendations about screening procedures. Their ratings are used by Medicare and Medicaid to decide what's covered and for which patients. In turn, many private insurance companies cover the same procedures. The USPSTF explicitly doesn't consider cost in their recommendations. Most often, they look at whether a screening reduces mortality rates.
1: https://www.uspreventiveservicestaskforce.org/
But you're not having cancer checked out, you're having a "spot" or a "nodule" or something checked out.
And the person that's making the recommendation on whether or not to check it out may get sued for $10M if they tell you it's probably nothing and they're wrong, but have no harm come to them if they tell you it's worth having some other doctor do a biopsy.
And they might make an extra couple hundred bucks every time you have to come back and see them to follow up on this spot.
And the radiologist interpreting the MRIs... the same perverse incentives regarding how they interpret a "spot."
Insurance-based medical systems mean the patient has transferred responsibility for saying no to those actually paying the bills. They have to draw the line somewhere.