Monday, February 15, 2016

E-cigs: promise & perils

- Jennifer Middleton, MD, MPH

Do e-cigarettes containing nicotine help patients quit smoking? A Cochrane for Clinicians in the February 1 issue of AFP reports that their efficacy is better than placebo and roughly equivalent to nicotine patches in helping patients quit. The U.S. Preventive Services Task Force (USPSTF), however, takes a less definitive stance, and providers must weight the possible benefits of e-cigs against the risk of them leading to tobacco smoking initiation among youth.

The Cochrane systematic review identified 13 studies that met their inclusion criteria, 11 cohort studies and 2 randomized controlled trials (RCTs). The placebo in these 2 RCTs was an e-cigarette that did not contain nicotine; 1 study also compared e-cigarettes containing nicotine to the nicotine patch. Pooling the results from these 2 studies, the reviewers found that more participants quit tobacco cigarettes for at least 6 months using e-cigarettes containing nicotine than those who did not (relative risk 2.29, 95% confidence interval [CI] 1.05 to 4.96). The RCT comparing e-cigarettes to patches found no difference in quit rates, though a significant number of e-cig participants did decrease their overall tobacco usage compared to those using the patch. Low event rates led to wide CIs in the RCTs and cohort studies, and the reviewers described their overall confidence in their findings as low, citing both the wide CIs and the overall small number of studies done to date.

The USPSTF gives an "I" grade (insufficient evidence to assess balances of benefits and harms) to recommending e-cigarettes containing nicotine for tobacco cessation; the evidence base just isn't rigorous enough yet to meet their standards. One of those potential harms revolves around youth use. Although most states do not permit e-cigarette sales to minors, use in the under-18 age group is rising. Even more troubling, adolescents who have ever tried e-cigarettes containing nicotine are twice as likely to eventually try smoking tobacco cigarettes. The risk increases with younger age; 11 to 13-year-olds are four times as likely to eventually try smoking tobacco.

E-cigarettes containing nicotine may be useful for tobacco harm reduction in adults who currently smoke, but their availability may be increasing the number of adolescents who start smoking tobacco. Physicians who care for adolescents do a good job of screening for tobacco use, but few are asking specifically about e-cigarette use. Many adolescents believe that e-cigarettes are not only safer than tobacco cigarettes but are more socially acceptable.

As family physicians, we have the opportunity to interact both with adults who want to quit smoking and adolescents whom we hope to keep from initiating tobacco smoking. These studies provide some early guidance while we await further research: e-cigarettes containing nicotine may help adult tobacco smokers quit, and we need to screen for e-cigarette use in our adolescents.

If you'd like to read more, here's a 2014 AFP editorial on e-cigarettes, a 2015 AAFP FMX presentation on e-cigarettes, and the AAFP's Healthy Interventions Tobacco and Nicotine Toolkit.

How are you talking with your patients about e-cigarettes?

No comments:

Post a Comment