Clinical application of a simple questionnaire for the differentiation of asthma and chronic obstructive pulmonary disease.
BACKGROUND
Asthma and chronic obstructive pulmonary disease (COPD) are highly prevalent chronic diseases characterized by airflow limitation. Both diseases have a distinct pathogenesis and require unique treatment approaches. Due to some common characteristic traits, asthma and COPD are often lumped together in clinical practice. We sought to develop a simple questionnaire for the distinction of asthma and COPD.


METHODS
Clinical discriminants of asthma and COPD were retrospectively identified by multiple logistic regression using files from 547 consecutive adult patients presenting to a pulmonary specialist practice with a diagnosis of asthma or COPD. With these features, we generated a simple quantitative questionnaire supporting a diagnosis of COPD with high scores and asthma with low scores (range 0-15 points). Questionnaire results were compared with physician's diagnosis based on GINA and GOLD guidelines including skin tests, spirometry and reversibility data.


RESULTS
210 patients had COPD and 337 had asthma. Age of onset, smoking history, atopy status, and cough quality were significantly associated with a diagnosis of asthma or COPD. Questionnaire scores for COPD patients were higher than those for asthmatics (mean score 10.5+/-0.18 vs. 4+/-0.12, P<0.0001). Receiver operational characteristics (ROC) analysis revealed a cutoff score of 7 with the highest discriminant power (87.6% sensitivity, 87.2% specificity for COPD, 87.4% correctly classified, area under the ROC curve: 0.954). The overlap between asthma and COPD (score 6-8) comprised about 20% of the total population, these patients included a higher proportion of COPD patients with atopy, and smoking asthmatics.


CONCLUSIONS
In patients with obstructive airway diseases, a simple questionnaire can support the differentiation of asthma and COPD in everyday clinical practice. Further prospective trials are necessary to confirm these initial observations.
Beeh
Kai Michael
KM
Pulmonary Department, Internal Medicine, University Hospital Mainz, Lagenbeckstr. 1, Mainz 55131, Germany. k.beeh@3-med.klinik.uni-mainz.de
Kornmann
Oliver
O
Beier
Jutta
J
Ksoll
Michael
M
Buhl
Roland
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires