Kinney GL, et al. - Researchers tested their hypothesis that the combination of pulmonary function testing (PFT) and computed tomography (CT) phenotypes would provide a more powerful tool for assessing underlying morphologic differences associated with pulmonary function in Chronic Obstructive Pulmonary Disease (COPD) than PFT alone. Factor analysis of 26 variables was used to classify 8,157 participants recruited into the COPDGene cohort between January 2008 and June 2011 from 21 Clinical Centers across the United States. They identified that 5 factors explained 80% of the covariance and represented domains for increased emphysema and decreased pulmonary function (Factor 1); airway disease and decreased pulmonary function (Factor 2); gas trapping (Factor 3); CT variability (Factor 4); and hyperinflation (Factor 5). Factors 1 through 4 were noted to be associated with mortality and there was a significant synergistic interaction between Factor 1 and Factor 2 on mortality over 46,079 person-years of follow-up. Patients at particularly high risk for mortality could be identified via considering CT measures along with PFT in the assessment of COPD.