What it does to the appointment

Imagine a GP with ten minutes and a screen. The screen says you've been on a blood pressure tablet since March. The reading today is high. The screen's story is that the tablet isn't working, and the sensible next step on that story is a second tablet, or a higher dose, or a different one. The true story is that the tablet's been in a drawer since April, and the reading today is just what your blood pressure is. Ten minutes go on the wrong problem, you leave with a prescription for a medicine you didn't need, and the packet that started it all is still in the drawer.

This is the cost that the feeling-fine test hides best, because it doesn't fall on you in the moment. It falls on the quality of every decision made about you from then on. The prescriber is steering by a map that says you're taking the tablets, and every turn they make is taken from a position you're not in. Blood tests get read against doses you're not on. Side effects get attributed to the wrong thing. A medicine gets called ineffective when it was never tried.

I think this is why the conversation in chapter 20 is the book's whole method and not one tip among several. Nothing else fixes the map. You can take the tablets from tomorrow and the map is still wrong about the last five months. You can stop for good and the map still shows you on them. Only telling the prescriber what actually happened puts the appointment back on the real problem, and the real problem is usually smaller than the invented one. "I stopped because they made me dizzy" is a ten-minute problem with a known solution. "The tablets aren't working" is a year of escalating doses.

It helps, I think, to notice that the prescriber has heard it before. Half of all doses go untaken, across every condition anyone has studied. Nobody in a surgery is surprised by a drawer. What they can't work with is a drawer they don't know about.