Do respiratory symptoms predict chronic airflow obstruction and bronchial hyperresponsiveness in older adults?

Respiratory symptoms are common in older adults. In young populations the predictive value of such symptoms for chronic airflow obstruction and bronchial hyperresponsiveness is low. We investigated whether symptoms predict airflow obstruction and bronchial responsiveness in adults aged 45-86 years.

An age-stratified random sample of white adults aged 45 years and older was obtained from family doctor lists in Central Manchester, UK, and sent a respiratory symptoms questionnaire (exclusions: housebound, confused). Responders were invited to participate in a methacholine challenge (Newcastle dosimeter method; exclusions: ischemic heart disease, oral steroids, anticholinergic or beta-blocker medication).

Of 783 eligible subjects, 723 responded (response rate 92.3%). Symptoms were reported by 53.8%. Methacholine challenge was completed by 208 subjects. Sixty-five (26.4%) had chronic airflow obstruction, of whom 76.6% reported respiratory symptoms. Bronchial hyperresponsiveness (PD20 < or = 100 micrograms) was present in 26.0% of subjects overall, and in 36.8% of symptomatic and 14.6% of asymptomatic subjects (p < .001). Of those with bronchial hyperresponsiveness, 26.4% were asymptomatic. Predictive values of symptoms for chronic airflow obstruction and bronchial hyperresponsiveness were low.

Respiratory symptoms, chronic airflow obstruction, and bronchial hyperresponsiveness were all common in this adult population sample. However, the predictive value of symptoms for airflow obstruction/bronchial hyperresponsiveness was low. It was concluded that respiratory symptoms do not identify adults with airflow obstruction or bronchial hyperresponsiveness. Investigation by spirometry and peak flow monitoring is necessary to guide appropriate management.