In Reply In their letter in response to our Original Investigation,¹ He and Niu suggest that the association between frequency of electronic cigarette (EC) use and smoking level may be dose dependent, which our study did not investigate. This is a valid point, as frequency of EC use, and therefore the nicotine dose received, might be relevant with regard to smoking cessation. Unfortunately, such measures are difficult to obtain in large cohort studies such as CONSTANCES (Consultants des Centres d’Examens de Santé). Some vapers take a few puffs several times a day, while others use their ECs less frequently but take more puffs each time.² Additionally, other factors might also influence frequency of EC use, such nicotine dependency, nicotine dose in the e-liquid used, lengths and strength of puffs, as well as context and location of use (eg, festive, social, work, home). Prior studies of smoking cessation have considered daily EC use to be intensive,^3,4 yet future research will need to yield more detailed information about the relationship between the level of use and smoking patterns in large community-based samples.

在答复中他们对我们的原始调查的回复¹ He和Niu建议使用电子烟（EC）的频率与吸烟水平之间的关联可能与剂量有关，而我们的研究并未对此进行调查。这是一个有效的观点，因为EC的使用频率以及因此接受的尼古丁剂量可能与戒烟有关。不幸的是，在诸如CONSTANCES（高级研究中心顾问）之类的大型队列研究中很难获得这样的措施。有些vaper一天几次吸几次烟，而另一些va则很少使用EC，但每次吸更多的烟。²另外，其他因素也可能影响EC使用的频率，例如尼古丁依赖性，所用电子液体中的尼古丁剂量，抽吸的长度和强度以及使用的环境和位置（例如节日，社交，工作，家庭） 。戒烟此前的研究认为，每天使用EC是密集的，^{3 ，4}但未来的研究将需要获得有关使用水平和吸烟模式大型社区样本之间的关系更详细的信息。