The Lung Health Study used 35 years of age as its lower limit; this choice was justified by the relatively high proportion of patients aged 35 to 39 years (12%) included in the trial. It is possible, however, that COPD is detectable in even younger patients. In a study of tobacco and marijuana smokers with an average age of 33 years, about 25% had chronic cough and sputum production, 35% had wheeze and 10% had at least one acute bronchitis attack per year.
That even younger patients may be symptomatic is a reminder that spirometry screening is not an absolute substitute for the medical history and a physical examination. As demonstrated by Badgett and co-workers , moderate COPD can be diagnosed by internists with reasonable accuracy using breath sounds and the patient’s history. Holleman and Simel reviewed the predictive value of clinical examination and concluded that the clinician’s ability to diagnose airflow limitation is variable but seems to improve as the severity of the disorder increases.