Objective: To determine the extent of chronic obstructive pulmonary disease (COPD) hospitalization in easily identifiable high-risk subgroups within a typical primary care practice.

Design: Prospective cohort analysis of administrative claims data.

Setting: British Columbia.

Participants: British Columbia residents who were 50 years or older on December 31, 2014, and received a physician diagnosis of COPD between 1996 and 2014.

Main outcome measures: Rate of acute exacerbation of COPD (AECOPD) or pneumonia hospitalization in 2015, broken down by risk identifiers including previous AECOPD admission, 2 or more community respirologist consultations, nursing home residence, or none of these.

Results: Of the 242,509 identified COPD patients (12.9% of British Columbia residents ≥50 years), 2.8% were hospitalized for AECOPD in 2015 (0.038 AECOPD hospitalizations per patient-year). The 12.0% with prior AECOPD hospitalization accounted for 57.7% of new AECOPD hospitalizations (0.183 hospitalizations per patient-year); the 7.7% with respirologist involvement accounted for 20.4% (0.102 hospitalizations per patient-year); and the 2.2% in nursing homes accounted for 3.6% (0.061 hospitalizations per patient-year). Those with any of the 3 risk identifiers accounted for only 1.5% more COPD hospitalizations (59.2%) than those with prior AECOPD hospitalization, suggesting prior AECOPD hospitalization is the most important indication of risk. A typical primary care practice held a median of 23 (interquartile range=4 to 65) COPD patients, of whom roughly 20 (86.4%) had none of these risk identifiers. This low-risk majority had only 0.018 AECOPD hospitalizations per patient-year.

Conclusion: Most AECOPD hospitalizations occur in patients with previous such admissions. When time and resources are limited, COPD initiatives targeting primary care practices should focus more on the 2 to 3 patients with prior AECOPD hospitalization or more symptomatic disease, and less on the low-risk majority.