Exacerbations in the pre- and post-COPD diagnosis periods.

Purpose: Chronic obstructive pulmonary disease (COPD) is usually recognized in its later stages, delaying therapeutic opportunities. Screening questionnaires have modest sensitivities and specificities. Adding questions about prior respiratory events might improve screening characteristics.

Methods: Using administrative data from all health care facilities in Olmsted County, Minnesota USA, we identified all adults with an initial diagnosis of COPD from 2005 through 2007. For each individual we identified all coded lower and upper respiratory events in the 2 years before and the 2 years after the COPD diagnosis and categorized them as probable or possible COPD exacerbations.

Results: 356 women and 346 men (N = 702) with a mean age of 67.5 years and 66.6 years respectively had a first diagnosis of COPD during the study period. Respiratory events in the 2 years prior to a COPD diagnosis were common with a range of 0 to 16 events per individual and a mean (SD) of 2.04 (2.14), 1.38 (1.86) all of which were probable COPD exacerbations. Prediagnostic respiratory events were predictive of similar events in the post diagnostic period (odds ratio = 1.6, 95% confidence interval [CI] 1.3 to 1.8).

Conclusion: Inquiring about the number and type of upper or lower respiratory events in the 2 past years may be a useful addition to the "screening" criteria to improve COPD identification, especially those at risk of frequent exacerbations.