Methods
A retrospective electronic chart review from outpatient clinics in a large, integrated health
care system serving urban and rural eastern Wisconsin was conducted. Just over 55,000
patients (pneumonia= 4907; bronchitis= 32,760; URTI= 20,037) aged 18–80, diagnosed
with pneumonia, bronchitis and upper respiratory infection from all outpatient facilities from
January 2005 to December 2006, were identified. Medical records of 604 consecutive,
randomly selected patients based on clinical ICD-9 codes were compared: 200 with
clinically diagnosed pneumonia (ICD-9-486.0); 205 with acute bronchitis (466.0); and 199
with URTI (460.0–465.9). Subjects diagnosed with cancer, bronchiectasis, blood disorder,
tuberculosis, HIV/AIDS and pregnant women were excluded from this study. Patients with
acute exacerbations of chronic bronchitis were omitted from the acute bronchitis group after
univariate analysis.