To the Editor.
—We are concerned about the conclusion that Dr Lee-Feldstein and colleagues1 reached about poor breast cancer survival in health maintenance organization (HMO) hospitals in Orange County, California. As the largest hospital-based HMO in Southern California, Kaiser Permanente for years has supported comparison of medical outcomes of all health care organizations. Therefore, we believe it is mandatory for us to provide an accurate reflection of our breast cancer statistics for stage at diagnosis and survival.The Kaiser Permanente Medical Care Program in Southern California has operated its own hospital-based cancer registries for more than 40 years. All but two of our 10 registries are certified by the American College of Surgeons. At all our registries, follow-up rates are more than 97%. The data on stage at diagnosis and survival rate are derived from this rich and unique data source.We analyzed 7819 patients with newly diagnosed breast