Key points are not available for this paper at this time.
From the School of Health Related Professions (Dr Gerald); and the Lung Health Center, Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham (Dr Gerald, Dr Bailey), Birmingham, Alabama. Address correspondence to: Lynn B. Gerald, PhD, MSPH, University of Alabama at Birmingham, Lung Health Center, NHB 104, 619 19th Street South, Birmingham, AL 35249-7337.
Gerald et al. (2002) studied this question.