OBJECTIVES: Chronic Obstructive Pulmonary Disease (COPD) is a respiratory disorder characterized by progressive, partially reversible, airway obstruction.  Chronic bronchitis (CB) is a subset of COPD.  We compared CB epidemiology and related resource utilization in Ontario, between 2003 and 2009. METHODS: A 10-year database containing 176,000 patient records, from 53 general practitioners, was used to extract COPD records.  Index dates were July 2003 and July 2009 for patients aged 40+.  Prevalence was based on a diagnosis of COPD and CB defined by 1)ICD9/ICD10 codes; 2)Symptoms (chart text entries); or 3)Unique COPD drug therapy (i.e. anticholinergics).  Disease severity stratification for CB patients was based on 2008 Canadian Thoracic Society guidelines for patients with spirometry (12 months prior to index date) documenting FEV1 and FEV1/FVC of <0.7.  Related resource utilization (12 months prior to index date): specialists visits, ER visits, hospitalizations, were captured.  Comparisons between 2003 and 2009 are reported. RESULTS: In 2003, 76,143 records were examined and 6742 COPD patients were identified (8.9% prevalence, 63% diagnosed with CB, mean age 71±8) compared to 8.5% prevalence in 2009 (8495 patients/99,941 records; 66% with CB, mean age 69±9).  74% and 66% of CB patients have spirometry for stratification in 2003 and 2009 respectively. Severity stratification (CB patients) into mild, moderate, severe and very severe for 2003 was: 54%, 15%, 10%, 21% and in 2009: 52%, 22%, 7%, 18%.  There were 674 CB related hospitalizations in 2003 and 589 in 2009, using the spirometry subgroup.  From these hospitalizations: 32% vs 25% (2003 vs 2009); 43% vs. 46% and 19% vs. 25% were found in moderate, severe and very severe groups respectively. Differences between ER and specialist visits were also noted. CONCLUSIONS: CB constitutes the majority of COPD prevalence.  Resource utilization from 2003 and 2009 remained high despite perceived improvements in COPD/CB management.