I'm channeling Don Quixote today and I posted the following in panix.chat.politics (which you can only read if you're a panix member), which isn't a place well known for careful or respectful readers. It will probably only get scoffed at there, so I figured I would post it here too.
Recent news reports discuss two recent medium-term studies on weight-loss surgery. The Wall Street Journal article about the studies is here. Begin post:
The US study's control group isn't people, it's driver's licenses. So it doesn't control for socioeconomic status. During the period of time the study was conducted, insurance companies usually didn't pay for the operation. The operation costs $20,000 and up. Therefore the people having the surgery were relatively wealthy. Wealthy people have better health than poor people because they have better access to health care and less stress. As for the supposedly "matching" weights of the control group -- well, I don't know anyone who puts their real weight on a drivers license, or bothers to change the weight on their license when their real weight changes. So the control group is pretty meaningless.
The Swedish study showed a 1 percent lower risk of death (5% instead of 6%) for the surgical group over either 7 or 10 years, I forget which. Given that the surgery carries a double-digit risk of side effects that put a person back in the hospital (even bariatric surgeons admit this), it doesn't seem like the improvement in odds is worth getting the surgery for.
Both studies showed that the surgery patients had a 1.5 times greater risk of dying from accidents or suicide than the non-surgery patients. As far as I know, the studies didn't bother to look into this phenomenon, but two possible causes: the surgery and its attendant malnutrition is known to increase the risk of mental problems, and some malnutrition is known to increase the risk of mental problems, and some surgery patients develop alcoholism. Also, some of the surgery side effects are very painful. (I know someone who had the surgery and committed suicide in part because she developed rickets, which are very painful.)