Asthma in adult patients presenting with symptoms of acute bronchitis in general practice

Abstract

Objectives - To investigate the association between asthma and acute bronchitis in adults and to ascertain criteria to help general practitioners (GPs) differentiate between acute bronchitis and asthma. Design - Descriptive study. Setting - Primary health care centre in The Netherlands. Patients - 192 patients, aged 18-75 years, not known to have asthma or other pulmonary diseases, attending their GP with cough persisting for at least 2 weeks. Methods - Patients were considered to have asthma or chronic obstructive pulmonary disease on the basis of a questionnaire on respiratory symptoms, spirometry and methacholine challenge testing. They were classified as having acute bronchitis if, according to international guidelines, coughing was more frequent than normal for at least 2 weeks, but no more than 4 weeks. Furthermore, either expectoration of purulent sputum for a maximum of 2 weeks and/or rhonchi as assessed by auscultation had to be present. By means of logistic regression symptoms, signs and peak expiratory flow measurements were sought to predict which patients with acute bronchitis actually had asthma. Results - Of the 80 (41.7%) subjects with symptoms of acute bronchitis, 29 (36.9%) were patients with asthma. Within the acute bronchitis group, female sex and symptoms of current reported wheeze, reported episodes of attacks of dyspnoea over the last year and symptoms elicited by allergens were of help in identifying patients who actually had asthma. Conclusions - A considerable proportion of the patients presenting with acute bronchitis are actually patients with asthma. The absence or presence of a few symptoms and female sex may help to differentiate between these disorders.