Long-term outcomes in mild/moderate chronic obstructive pulmonary disease in the European community respiratory health survey.
BACKGROUND
Little is known about the long-term outcomes of individuals with mild/moderate chronic obstructive pulmonary disease (COPD) according to spirometric criteria.


OBJECTIVE
To test whether nonsmokers and asymptomatic subjects with a spirometric diagnosis of COPD have a steeper decrease in lung function and higher hospitalization rates than subjects without airway obstruction.


METHODS
A total of 5,205 subjects without asthma (20-44 years of age) from the general population, with FEV(1) >or= 50% predicted at baseline, were followed for 9 years in the frame of an international cohort study. Percent decrease in FEV(1) (DeltaFEV(1)%) and the annual hospitalization rate for respiratory causes during the follow-up were assessed for each subject.


RESULTS
At baseline, 324 (6.2%) subjects had the prebronchodilator FEV(1)/FVC ratio less than the lower limit of normal (LLN-COPD), and 105 (2.0%) subjects had the same ratio less than 0.70 (modified GOLD-COPD). At follow-up, smokers with LLN-COPD (n = 205) had a greater mean DeltaFEV(1)% (1.7%; 95% confidence interval [CI], 0.8-2.7) and a higher hospitalization rate (rate ratio [RR], 2.52; 95% CI, 1.65-3.86) than normal subjects. Similarly, symptomatic subjects with LLN-COPD (n = 104) had DeltaFEV(1)% (2.0%; 95% CI, 0.8-3.3) and the hospitalization rate (RR, 4.18; 95% CI, 2.43-7.21) higher than the reference group. By contrast, nonsmokers and asymptomatic subjects with LLN-COPD had outcomes that were similar or even better than normal subjects. Among subjects with LLN-COPD, the association of symptoms with DeltaFEV(1)% varied according to smoking habits (P = 0.007); it was particularly strong in symptomatic smokers and disappeared in symptomatic nonsmokers. Similar results were found with the modified GOLD classification.


CONCLUSIONS
In relatively young populations, COPD is associated with poor long-term outcomes in smokers and in symptomatic subjects only.
de Marco
Roberto
R
Sezione di Epidemiologia & Statistica Medica, Dipartimento di Medicina e Sanità Pubblica, Università degli Studi di Verona c/o Istituti Biologici II, Strada Le Grazie 8, 37134 Verona, Italy. roberto.demarco@univr.it
Accordini
Simone
S
Antò
Josep M
JM
Gislason
Thorarinn
T
Heinrich
Joachim
J
Janson
Christer
C
Jarvis
Deborah
D
Künzli
Nino
N
Leynaert
Bénédicte
B
Marcon
Alessandro
A
Sunyer
Jordi
J
Svanes
Cecilie
C
Wjst
Matthias
M
Burney
Peter
P
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006760:Hospitalization; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000628:therapy; D011897:Random Allocation; D012680:Sensitivity and Specificity; D012907:Smoking / Q000503:physiopathology; D013147:Spirometry; D016896:Treatment Outcome