Longitudinal and cross-sectional estimates of pulmonary function decline in never-smoking adults.
This paper describes methods for simultaneous cross-sectional and longitudinal analysis of repeated measurements obtained in cohort studies with regular examination schedules, then uses these methods to describe age-related changes in pulmonary function level among nonsmoking participants in the Six Cities Study, a longitudinal study of air pollution and respiratory health conducted between 1974 and 1983 in Watertown, Massachusetts; Kingston and Harriman, Tennessee; St. Louis, Missouri; Steubenville, Ohio; Portage, Wisconsin; and Topeka, Kansas. The subjects, initially aged 25-74, were examined on three occasions at 3-year intervals. Individual rates of loss increased more rapidly with age than predicted from the cross-sectional model. For example, for a male of height 1.75 m, the cross-sectional model predicted an increase in the annual rate of loss of FEV1 from 23.7 ml/yr at age 25 to 39.0 ml/yr at age 75, while the longitudinal model gave rates of loss increasing from 12.9 ml/yr at age 25 to 58.2 ml/yr at age 75. These results contrast with those of other studies comparing longitudinal and cross-sectional estimates of pulmonary function loss.
Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115.
J H
JH
Ware
D W
DW
Dockery
T A
TA
Louis
X P
XP
Xu
B G
BG
Ferris
F E
FE
Speizer
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001827:Body Height; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D012016:Reference Values; D012129:Respiratory Function Tests; D012907:Smoking