The patients that are being killed in the hospital? The insurance company is doing it based on genetic testing. Anyone who had been diagnosed with specific mutations in genes that are known to cause problems in the future, colon cancer, breast cancer, ovarian cancer, heart disease, etc., were being marked as too high of a risk and being killed.
Yep - that's exactly the book I needed to be reading as I am spending the next few months trying to turn around a BRCA mutation :)
Next time, no medical thrillers, even though they are some of my favorites. Maybe some nice, light and completely improbably Steven King.