Dozens of leading national medical institutions are proposing new diagnostic criteria for chronic obstructive pulmonary disease, the fourth leading cause of death in the United States.

In a new paper, the authors propose expanding diagnostic criteria from a standard single measure, lung function, to include environmental exposure, symptoms, and abnormal computed tomography scans. 

If used, the new criteria could increase the number of patients diagnosed with COPD by up to 36%, or about 5 million people, according to a new paper. The new diagnostic method would also increase the number of people who receive “tragically underutilized” pulmonary rehabilitation, according to the COPD Foundation.

The proposal is based in part on results from COPDGene, a multicenter observational study. In that study, participants who met either one, two or three additional criteria beyond smoking all had heightened odds of losing significant lung function in five years or of dying.

“If we diagnose COPD based only on impaired lung function, then we miss many patients in the early stages of the disease,” said senior author James Crapo, M.D., from National Jewish Health, Denver. “While some physicians do empirically treat patients with symptoms, many patients are not getting therapy that can improve their symptoms, their quality of life, and might extend their lives.”