The study cohort consisted of 12,761 female patients of Kaiser Permanente Northern California, aged 40 to 79 years, who attended voluntary multiphasic health checkups at the KP Oakland Medical Center between 1968 and 1973. Researchers compared the results of the mammograms with the discharge diagnoses of these women from hospitalizations from 1971 to 2000, and with the causes of death shown in the California Automated Mortality Linkage System (CAMLIS). Kaiser Permanente is America's leading integrated health care program.

Founded in 1945, it is a non-profit, multi-specialty, group-practice prepayment program serving the health care needs of 8.3 million members in nine states and the District of Columbia. The Kaiser Permanente Northern California Region has almost 3.2 million members. It includes 5,000 physicians in The Permanente Medical Group (TPMG) and about 54,000 employees.

Research conducted by scientists at the Kaiser Permanente Division of Research in Oakland, Calif. has appeared in the Journal of the American Medical Association, the New England Journal of Medicine, Pediatrics, the American Journal of Preventive Medicine and numerous other peer-reviewed medical journals. CONTACT: Kathleen Barco of Kaiser Permanente, 510-987-3900. kaiserpermanente