ACCP News Release
Contact: Kim Lynch (847) 498-8341[email protected]
For release: September 12, 2000
SIMPLE PULMONARY TEST CAN PREDICT OVERALL LONG-TERM SURVIVAL
A new study showing that a simple pulmonary function test can predict overall long-term survival rates in both men and women appears in the September issue of CHEST.
Writing in the monthly peer-reviewed scientific journal of the American College of Chest Physicians, Holger J. SchUnemann, M.D., M..S., Department of Social and Preventive Medicine, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, in association with four colleagues, studied survival rates based on a standard pulmonary function test called forced expiratory volume in one second (FEV1), expressed as a percent of predicted normal.
The lung function test was performed on a randomly selected sample of 554 men and 641 women in 1960 - 1961 during the Buffalo Health Study, which was designed originally to investigate factors related to hypertension and pulmonary function. The participants were ages 20 to 89 years at baseline. Records were analyzed to determine whether they were living or dead, as well as to determine the cause of the recorded death .
No previous study had reported an association between lower levels of pulmonary function and all-cause mortality for a follow-up period of 29 years.
In their research, the investigators sought to determine the time span over which pulmonary function remained a significant predictor of mortality. They performed sequential survival analysis among the participants who had minimal survival times of 5, 10, 15, 20, and 25 years after enrollment in the study.
"In females involved in this study," said Dr. SchUnemann, "pulmonary function was a predictor of all-cause mortality for a period longer than 25 years. In male participants, pulmonary function lost its predictive value after 20 years."
When FEV1 scores were divided into five different levels of percent predicted values, participants in the lowest quintile experienced significantly higher all-cause mortality than did those in the highest 20 percent. The hazard risk ratio in the lowest quintile of the pulmonary function test for death from ischemic heart disease was over 2 to 1 for men and almost that level for women as compared to others in the highest quintiles. .
During the entire follow-up period, 54.5 percent of the men and 43.4 percent of the women died. According to the investigators, both genders died predominately from cardiovascular disease (53.5 percent), with ischemic heart disease (39 percent in men and 28 percent in women), in particular, representing the predominant cause of death. Respiratory disease was found to be the underlying cause of death in 9.6 percent of the men and 3.6 percent of the women.
The analyses were adjusted for significant risk factors for heart disease, including body mass index, systolic blood pressure, gender, education, and smoking status. The researchers point out, however, they had no information on another significant risk factor, serum cholesterol level.
"It is not clear in this study," said Dr. SchUnemann, "whether the observed association reflects a cause-effect relationship with mortality. However, the lung is a primary defense organ against environmental toxins, and impaired pulmonary function could lead to decreased tolerance against these environmental toxins."
To determine whether subjects were alive or dead, the research team undertook computer-based searches of the New York State Department of Health Vital Records Death Registry, the Cancer Tumor Registry, the Department of Motor Vehicles records of drivers licenses and auto registrations, the U.S. Social Security Administration death master files, and manual searches of the telephone directories of the city of Buffalo.
They also attempted to contact participants' last employers, neighbors, churches or other contact points if listed on the study's original questionnaire. Living participants were followed-up with direct telephone and mail contact or through relatives and other persons such as nursing home personnel.
According to Dr. SchUnemann, it is urgent to reach a better understanding of the relationship of impaired pulmonary function to disease in order to undertake preventive measures. He said that we know from several studies that smoking cessation does not seem to be the only answer because the risk from low pulmonary function is found also in never-smokers.
CHEST is published by the American College of Chest Physicians, which represents 15,000 members who provide clinical, respiratory, and cardiothoracic patient care in the U.S. and throughout the world.______________________________________________________________
Reporters may wish to contact Kimberly Lynch of the ACCP at (847) 498-8341 for a copy of the article. She can also be reached by email at [email protected]. Dr. Schnemann can be reached by phone at (716) 898-5792 or by email at [email protected].
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