To reveal the association of initial pulmonary function level with subseque
nt mortality and participation in a follow-up reexamination, a prospective
cohort study was performed. Female residents in a volcanic area of southern
Kyushu, Japan, were followed up for their vital status and the pulmonary f
unction 15 years after they received the first pulmonary function test. A c
ohort of 512 Japanese female residents who were examined for pulmonary func
tion as indicated by forced expiratory volume and forced expiratory volume
in one second was measured in a baseline examination in 1980. After 15 year
s, 35 females were lost to follow-up. Of the remaining 477 females, 340 and
137 females provided good and poor levels of pulmonary function tests (PFT
) at baseline, respectively. Mortality by 1995 in the poor PFT group was si
gnificantly higher than that in the good PFT group (33.6% vs 9.4%). The mor
tality differences were still highly significant when the 35 lost cases wer
e included as all alive. Among the 399 survivors, the nonparticipation rate
in the reexamination in 1995 was significantly higher in the poor PFT grou
p than that in the good PFT group (80.2% vs 69.5%). The results of the pres
ent study, a longitudinal study of pulmonary function, provide evidence of
selection effects due to death or failure to participate in a subsequent re
examination. (C) 1999 Academic Press.