Mortality and Marijuana
March 14, 1997--In an exhaustive study of ten years of mortality data for over 65,000 men and women, Kaiser Permanente research scientists found no statistically significant association between marijuana smoking and death.
The study, entitled "Marijuana Use and Mortality," is being published in the April 1997 issue of the American Journal of Public Health. The April issue, however, was printed late and is being released this week.
The lead scientist in the research was Stephen Sidney, MD, senior epidemiologist with the Division of Research in Kaiser Permanente's Northern California Region.
"About one-third of the American population over the age of 12 is estimated to have used marijuana, making it the most popular illegal drug in this country, but we still know little about its long-term health effects," Dr. Sidney said. "This report is the first of several to come from a major epidemiological investigation into the health consequences of Cannabis."
The study population comprised 65,171 patients between the ages of 15 and 49 who had multiphasic health check-ups at the Oakland and San Francisco Kaiser Permanente facilities between 1979 and 1985. Based on answers about drug use given in a confidential self-administered research questionnaire, the patients were divided into groups ranging from those who had never tried marijuana to those who used it currently and regularly. Mortality statistics for all patients were followed until 1991 and analyzed for any association between marijuana and death. The study's statistical methodology controlled for the use of tobacco and alcohol so that deaths from marijuana smoking could be clearly identified.
In men, the study found, marijuana use was associated only with deaths from AIDS. There was no significant increase in deaths from other causes.
"This doesn't mean that marijuana causes AIDS," Dr. Sidney pointed out. "Prior research has shown that during the 1980s homosexual and bisexual men had a higher rate of marijuana use than heterosexual men. We think this is the reason for the link between marijuana use and AIDS. It's the sexual activity, not smoking marijuana, that causes the disease."
The study also found that, among women, the risk of accidental death rose to an almost statistically significant level.
"We have submitted to medical journals two more reports on marijuana use and health, one focusing on cancer and the other on emergency room and medical office visits for injury," Dr. Sidney said. "We expect to prepare later this year additional reports on respiratory illness and hospitalization for injuries."
The research study into marijuana and mortality was supported principally by a grant from the National Institute on Drug Abuse. Additional funding came from the National Cancer Institute and The Alcoholic Beverage Medical Research Foundation.
In addition to Dr. Sidney, the study's authors included Irene S. Tekawa, MA, Charles P. Quesenberry, Jr., PhD, and Gary Friedman, MD, all of Kaiser Permanente's Division of Research; and Jerome E. Beck, DrPH, of the School of Public Health, University of California, Berkeley.
The California Division of Kaiser Permanente is a prepaid, health maintenance organization (HMO) serving more than 5 million members throughout the state. The Division has approximately 6,400 physicians and 55,000 employees. It is organized into 12 local market areas which are served by 26 major medical centers.
Kaiser Permanente News Bureau
Tom Debley, Lila Petersen or Laura Rohde, 510/987-3900