Center for Behavior and Health, Departments of Psychiatry and Psychological Science, University of Vermont, Burlington, VT.
Nicotine Tob Res. 2020 May 26;22(6):867-871. doi: 10.1093/ntr/ntz042.
This review examines the evidence for the hardening hypothesis; that is, the prevalence of (1) becoming a former smoker is decreasing over time due to (2) decreased quit attempts, or (3) decreased success on a given quit attempt.
PubMed, EMBASE, PsychINFO, trial registries, and other databases were searched for population-based surveys that reported whether one of the aforementioned three outcomes decreased over time.
None of the 26 studies found that conversion from current to former smoking, number of quit attempts, or success on a given quit attempt decreased over time and several found these increased over time. These results appeared to be similar across survey dates, duration of time examined, number of data points, data source, outcome definitions, and nationality.
These results convincingly indicate hardening is not occurring in the general population of smokers. On the other hand, the prevalence of smoking is declining less among older and women smokers, and smokers with low education, low income, psychological problems, alcohol or drug abuse, medical problems, and greater nicotine dependence, than among those without these characteristics, presumably due to less quitting. Why this has not lead to decreased success in stopping smoking in the general population is unclear.
Some have argued that a greater emphasis on harm reduction and more intensive or dependence-based treatments are needed because remaining smokers are those who are less likely to stop with current methods. This review finds no or little evidence for this assumption. Psychosocial factors, such as low education and psychiatric problems, predict less ability to quit and appear to becoming more prevalent among smokers. Why this is not leading to decreased quitting in the general population is an anomaly that may be worth trying to understand.
本综述考察了硬化假说的证据；也就是说，（1）由于（2）戒烟尝试减少或（3）特定戒烟尝试成功率降低，曾经吸烟者成为前吸烟者的比例随着时间的推移而减少。
通过 PubMed、EMBASE、PsychINFO、试验登记处和其他数据库，检索了报告上述三种结果中是否有一种随着时间的推移而减少的基于人群的调查。
没有一项研究发现，从不吸烟者变为前吸烟者、戒烟尝试次数或特定戒烟尝试成功率随着时间的推移而减少，反而有几项研究发现这些比率随着时间的推移而增加。这些结果在调查日期、研究时间段、数据点数量、数据来源、结果定义和国籍方面似乎相似。
这些结果令人信服地表明，硬化现象在一般吸烟人群中并未发生。另一方面，在老年和女性吸烟者、教育程度低、收入低、存在心理问题、酗酒或吸毒、有医疗问题和尼古丁依赖程度高的吸烟者中，吸烟率的下降速度低于没有这些特征的吸烟者，这可能是因为戒烟的人少了。为什么这并没有导致一般人群戒烟成功率的降低，目前还不清楚。
有人认为，需要更加重视减少危害和更密集或基于依赖的治疗，因为目前的方法对那些不太可能戒烟的吸烟者效果较差。本综述没有发现或几乎没有证据支持这一假设。社会心理因素，如教育程度低和精神问题，预测戒烟能力较差，而且似乎在吸烟者中越来越普遍。为什么这并没有导致一般人群戒烟率的降低，这是一个反常现象，可能值得尝试理解。
