Interestingly, Erickson's research came to the opposite conclusion of a study done in California: HMO patients there were more likely to get bypass surgery in a low-death-rate hospital than were their fee-for-service counterparts. A possible explanation, Erickson says, is that in California many hospitals perform only a small number of bypass operations. Low volume is often considered a marker for lower quality, and thus HMOs may choose to avoid doing business with such institutions.
On the other hand, New York requires that all hospitals doing bypass surgery have a high volume, making it ideal for this type of study. "I don't particularly think the HMOs are being malicious. I suspect that their response to this will be to say, 'Hey, this is great. Here's something we can do better,'" Erickson says.
But Laura Diamond, a spokeswoman for the American Association of Health Plans, an industry group, tells WebMD that the study is flawed. Diamond says that since the average death rate in New York hospitals was just 2.44%, the researchers' designation of high- and low-mortality hospitals was "arbitrary."
"Given the small difference in mortality rates, it's unlikely that patient outcomes were affected in a significant manner. It's also not clear if any of the managed care plans limited their contracts to either high- or low-mortality centers," Diamond says.
- HMO patients who need heart bypass surgery are more likely to have the operation in hospitals that have a higher-than-average death rate than patients with insurance that pays for each procedure separately.
- Financial considerations may explain why HMO patients do not get to use the hospitals with the lowest death rates for bypass surgery, but this study does not prove that.
- One researcher says that information about health care quality is available and should be sought by patients.