IDENTIFYING ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY-DISEASE IN PATIENTS WITH PERSISTENT COUGH PRESENTING TO GENERAL-PRACTITIONERS - DESCRIPTIVE STUDY

Objective: To determine the prevalence of asthma and chronic obstructi ve pulmonary disease in patients not known to have these disorders, wh o present in general practice with persistent cough, and to ascertain criteria to help general practitioners in diagnosis. Design: Descripti ve study. Setting: Primary healthcare centre in the Netherlands. Subje cts: 192 patients aged 18-75 years, not known to have asthma or chroni c obstructive pulmonary disease, attending their general practitioner with cough persisting for at least 2 weeks. Methods: A diagnosis of as thma or chronic obstructive pulmonary was based on the recurrence of a irway symptoms in the past year accompanied by spirometric measurement s (including bronchodilator testing) and methacholine provocation test s. A scoring formula to estimate the probability of asthma or chronic obstructive pulmonary disease, based on history and physical examinati on, was generated by means of logistic regression. Results: 74 patient s (39%) were classified as having asthma, 14 (7%) as hating chronic ob structive pulmonary disease. The best formula for predicting asthma or chronic obstructive pulmonary disease used scores for three symptoms: (reported) wheeze, (reported) dyspnoea, and allergen induced symptoms , together with prolonged expiration, pack years of smoking, and femal e sex variables were scored 1 when present and 0 when absent except fo r allergen induced symptoms (1.5) and number of pack years of smoking (n/25). With a cut off value of 3 on the scoring formula 76% of the pa tients could be classified correctly. Conclusions: About half of patie nts with persistent cough who present to a general practitioner have a sthma or chronic obstructive pulmonary disease. With a simple formula based on three symptoms and prolonged expiration, pack years of smokin g, and female sex most patients may be identified correctly in general practice.