Detection of previously undiagnosed cases of COPD in a high-risk population identified in general practice.
OBJECTIVE
Under-diagnosis of COPD is a widespread problem. This study aimed to identify previously undiagnosed cases of COPD in a high-risk population identified through general practice.


METHODS
Participating GPs (n = 241) recruited subjects with no previous diagnosis of lung disease, >35 yrs, and at least one respiratory symptom. Age, smoking status, pack-years, BMI, dyspnoea score (MRC), and pre-bronchodilator spirometry data was obtained. Subjects with airway obstruction (FEV(1)/FVC ≤ 0.7) at initial spirometry were tested for reversibility, according to Danish COPD guidelines, with bronchodilator and, if necessary, corticosteroids in order to confirm a diagnosis of COPD.


RESULTS
A total of 4.049 (49% females) subjects were included; mean age 58 yrs, BMI 27, and 32 pack-years. The COPD prevalence was 21.7%; 8.3% in subjects younger than 48 years. Most patients were classified in GOLD stages I and II (36% and 50%, respectively). The number needed to screen (NNS) for a new diagnosis of COPD was 4.6. COPD diagnosis was related to gender, age, BMI (p < 0.001), pack-years, and cough (p < 0.001), wheezing (p < 0.001) and sputum production (p = 0.002). A threshold of 10% pre-test risk of COPD would have reduced the number of spirometry tests by 35% although 90% of the patients with COPD would still have been identified (NNS 3.9).


CONCLUSIONS
Of the at-risk subjects studied, 22% were diagnosed with COPD. A case-finding strategy providing questionnaire assessment and diagnostic spirometry to high-risk subjects in primary care, and therefore, identifies a large proportion of undiagnosed COPD patients, especially in the early stages of the disease.
Dept. of Respiratory Diseases, Århus University Hospital, Århus, Denmark.
Anders
A
Løkke
Charlotte Suppli
CS
Ulrik
Ronald
R
Dahl
Liane
L
Plauborg
Jens
J
Dollerup
Luise Cederkvist
LC
Kristiansen
Patrick Hagge
PH
Cording
Christian
C
Dehlendorff
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004417:Dyspnea / Q000453:epidemiology; D005260:Female; D058006:General Practice / Q000379:methods*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D013147:Spirometry