Incidence and determinants of moderate COPD (GOLD II) in male smokers aged 40-65 years: 5-year follow up.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is a major health problem with an estimated prevalence of 10-15% among smokers. The incidence of moderate COPD, as defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), is largely unknown.


OBJECTIVE
To determine the cumulative incidence of moderate COPD (forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC] <0.7 and FEV1 <80% predicted) and its association with patient characteristics in a cohort of male smokers.


METHODS
Prospective cohort study.


METHODS
The city of IJsselstein, a small town in the Netherlands.


METHODS
Smokers aged 40-65 years who were registered with local GPs, participated in a study to identify undetected COPD. Baseline measurements were taken in 1998 of 399 smokers with normal spirometry (n = 292) or mild COPD (FEV1/FVC <0.7 and FEV1 >or=80% predicted, n = 107) and follow-up measurements were conducted in 2003.


RESULTS
After a mean follow-up of 5.2 years, 33 participants developed moderate COPD (GOLD II). This showed an estimated cumulative incidence of 8.3% (95% CI = 5.8 to 11.4) and a mean annual incidence of 1.6%. No participant developed severe airflow obstruction. The risk of developing moderate COPD in smokers with baseline mild COPD (GOLD I) was five times higher than in those with baseline normal spirometry (one in five versus one in 25).


CONCLUSIONS
In a cohort of middle-aged male smokers, the estimated cumulative incidence of moderate COPD (GOLD II) over 5 years was relatively high (8.3%). Age, childhood smoking, cough, and one or more GP contacts for lower respiratory tract problems were independently associated with incident moderate COPD.
Geijer
Roeland M M
RM
Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, the Netherlands. r.geijer@umcutrecht.nl
Sachs
Alfred P E
AP
Verheij
Theo J M
TJ
Salomé
Philippe L
PL
Lammers
Jan-Willem J
JW
Hoes
Arno W
AW
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000209:etiology; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013147:Spirometry / Q000379:methods; D013997:Time Factors; D014797:Vital Capacity