Exclusive E cigarette Use Significantly Associated with COPD RT E Cigarettes Have No Benefit for COPD Patients Trying to Quit Smoking National Emphysema Foundation E cigarettes are Poor Substitutes for Conventional Smoking in COPD Patients Older users of e cigarettes at greater risk of respiratory illness, study suggests CUNY Graduate School of Public Health & Health Policy Electronic cigarette use and its association with asthma, chronic obstructive pulmonary disease (COPD) and asthma COPD overlap syndrome among never cigarette smokers