Martinez CH, Diaz AA, Parulekar AD, Rennard SI, Kanner RE, Hansel NN, Couper D, Holm KE, Hoth KF, Curtis JL, Martinez FJ, Hanania NA, Regan EA, Paine R, Cigolle CT, Han MK. Age-Related Differences in Health-Related Quality of Life in COPD: An Analysis of the COPDGene and SPIROMICS Cohorts. Chest. 2016 Apr; 149(4):927-35.