Should People Avoid Whole-Body Screening Info? - By Scott Alexander

TL;DR

• 1

  Whole-body MRI looks borderline, not absurd: Scott's rough model says 1,000 scans produce about 32 QALYs of benefit and 5 QALYs of harm, with $2.7 million in costs, which works out to roughly $108,000 per QALY.

• 2

  Most people screened do not clearly benefit: Out of 1,000 seemingly healthy people, 680 need no follow-up, 300 get mildly concerning findings, 20 get biopsies, and only 8 people total end up living longer and healthier because of what the scan found.

• 3

  The real fight is over false positives and human behavior: The analysis assumes patients and doctors can calmly ignore harmless findings, but Scott says anxiety, overtreatment, doctor shopping, and ordinary medical mistakes could quickly erase the paper gains.

• 4

  Ignoring ambiguous findings is not an easy fix: The 300 follow-ups in his model are already assumed to be rationally selected, and they are where 4 of the 8 true benefits come from, so raising thresholds also cuts real wins.

• 5

  A rich person who truly does not care about money may still rationally choose screening: Once you strip out the $2,000 scan cost, the expected benefit becomes about 0.024 QALYs versus 6.2 hours of time and small side-effect risk, which Scott says can look favorable for a very unusual person.

• 6

  Midjourney's ultrasound pitch is more an economics story than a medical one: He doubts ultrasound will obviously beat MRI on raw detection or false positives, but lower price, easier scaling, and Silicon Valley-style go-to-market could still make it attractive to consumers.