With great interest we read the contribution by Gershon and colleagues1 about chronic obstructive pulmonary disease (COPD)-related prevalence, incidence, and mortality in Canada. Their study is another example of how administrative databases can be powerful sources of research data. Nonetheless, after studying the article we felt that we should make some comments.
Bischoff EW, Crockett AJ, Schermer TRJ. Trends in Population Burden of COPD: Actual Facts or Fallacies?. Arch Intern Med. 2010;170(15):1408-1410. doi:10.1001/archinternmed.2010.259