E-Cigarettes Associated with Lower Quit Rates Among Smokers, Major Review Finds

Analysis of real-world use suggests vaping may hinder, not help, smokers trying to quit traditional cigarettes.

I. Introduction: Questioning Vaping's Role in Cessation

Electronic cigarettes (e-cigarettes), also known as Electronic Nicotine Delivery Systems (ENDS), have rapidly gained popularity worldwide. While many users cite quitting traditional cigarettes or navigating public smoking bans as key motivations, the actual effectiveness of these devices as cessation aids has been the subject of conflicting scientific evidence. Some clinical trials have previously suggested a benefit, while real-world observational studies hinted at the opposite.

A systematic review and meta-analysis published in the Lancet Respiratory Medicine by Kalkhoran and Glantz aimed to resolve this conflict by synthesizing data from both real-world usage and controlled clinical settings to assess the true association between e-cigarette use and successful cessation of traditional cigarette smoking in adults.

II. Contextualizing Cessation: The Low Success Rate of Quitting

To understand the significance of e-cigarette research, it is crucial to recognize the inherent difficulty of ending nicotine dependence. Overall, what percentage of smokers quit successfully in any given year remains low, typically less than 1 in 10 adults who attempt to quit (around 8.8% annually in the U.S.).

A. The Challenge of "Cold Turkey"

The most common method, quitting smoking cold turkey (unassisted cessation), is also one of the least successful. The success rate of quitting smoking cold turkey is generally estimated to be between 3% and 7% long-term. The dangers of quitting smoking cold turkey aren't physical harm, but rather the intensity of withdrawal symptoms (severe nicotine cravings, irritability, anxiety, and depression), which often lead to relapse.

B. NRT and Assisted Cessation

Pharmacological aids, such as varenicline or Nicotine Replacement Therapies (NRT) like the patch, are designed to manage withdrawal and increase success rates. The success rate of quitting smoking with the patch or other NRTs is typically higher than quitting cold turkey, often doubling the odds of quitting compared to unassisted attempts. However, even with the patch, long-term abstinence rates remain challenging, emphasizing that comprehensive support, including behavioral counseling and medication, offers the best chance of success.

III. Methodology: Synthesizing Real-World and Clinical Data

The researchers conducted a comprehensive literature search across PubMed and Web of Science, ultimately including 38 studies in the systematic review. Crucially, their meta-analysis focused on 20 studies that included a control group, allowing for a direct comparison of quitting success rates between smokers who used e-cigarettes and those who did not.

Key aspects of the methodology included:

• Primary Endpoint: Cigarette smoking cessation, validated either by self-report or biochemical verification.

• Comparison: E-cigarette users were compared directly against non-e-cigarette users.

• Rigorous Bias Check: The studies were assessed for potential biases using the ACROBAT-NRSI tool and the Cochrane Risk of Bias Tool.

IV. Primary Findings: E-Cigarette Use Hinders Quitting

The analysis yielded a robust and concerning conclusion: e-cigarette use was associated with significantly decreased odds of quitting traditional cigarettes.

A. The Critical Finding

Smokers who used e-cigarettes were found to have odds of successfully quitting cigarettes that were 28% lower than those who did not use the devices. This finding is summarized by the overall Odds Ratio (OR) of 0.72 (with a 95% Confidence Interval of 0.57–0.91).

B. Findings Consistent Across Groups

To ensure the finding was reliable, the researchers analyzed various sub-groups. The negative association remained stable across different study types and participant intentions:

• The effect was consistent whether the study focused on all smokers or only those who were actively interested in quitting.

• The finding was stable across different study designs (longitudinal studies, cross-sectional studies, and even the included clinical trials). This suggests the outcome is not simply an artifact of study design but reflects the actual effect of e-cigarette use as currently practiced.

V. Conclusion and Public Health Implications

A. Interpretation of Results

The study concludes that, in their current form and usage patterns, e-cigarettes are associated with significantly less quitting among adult smokers. When we consider how many smokers quit successfully each year—a very small fraction—this finding suggests that e-cigarettes are not adding to that number, but potentially interfering with cessation attempts. The discrepancy with a few earlier positive findings in highly controlled trials is likely due to the gap between a strict, monitored clinical experiment and the everyday, real-world consumption of a mass-marketed consumer product.

B. Public Health Recommendation

Based on this strong evidence, the researchers strongly recommend that e-cigarettes should not be recommended as effective smoking cessation aids until substantial, high-quality evidence emerges that demonstrates their efficacy in helping smokers quit in a real-world context.

Source Study Reference: Kalkhoran, S., & Glantz, S. A. (2016). E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis. Lancet Respir Med, 4(2), 116–128.