Accuracy of self-reported e-cigarette nicotine strength in young adults (18-26) and adults (27-54) who vape and differences in their preferences for nicotine strength and flavor.

PURPOSE: To examine the accuracy of self-reported nicotine strength and differences in nicotine strength and flavor preferences between young adults and adults who vape. Accurate assessment of nicotine exposure is essential for understanding vaping behavior and informing public health research, yet the reliability of self-reported nicotine strength remains unclear.

METHODS

We recruited 61 young adults (18-26) and 65 adults (27-54). Participants reported the nicotine strength of their vaping products (high vs. low) and provided product samples for laboratory analysis. Nicotine concentrations in the samples were measured using gas chromatography-mass spectrometry. Participants were asked about their preferred flavor and whether they prioritize nicotine strength or flavor when purchasing a product.

RESULTS

The agreement between self-reported and laboratory-derived nicotine strengths (Cohen's kappa) was 0.73 for young adults and 0.71 for adults. More young adults used high-nicotine products (≥24mg/mL) than adults (50.8% vs. 30.8%; p = 0.022). Most participants in both age groups used fruit/sweet products more than non-sweet (tobacco/menthol). However, nicotine strength was more frequently identified as the primary factor influencing product choice than flavor.

CONCLUSION

Among young adults who vaped regularly in this sample, self-reported nicotine strength showed substantial agreement with laboratory-derived low/high nicotine-strength categories, supporting its use for broad classification in research settings. Nicotine strength appeared to be more important for young adults than flavor. This study provides novel evidence that nicotine concentration plays a central role in vaping behavior and highlights the importance of regulating nicotine strength alongside flavors to reduce vaping rates among young people.