Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Nicotine Tob Res. 2013 May;15(5):978-82. doi: 10.1093/ntr/nts205. Epub 2012 Sep 18.
Smoking cessation is typically verified biochemically by expired-air carbon monoxide (CO) levels below 9 ppm (i.e., ≤8 ppm), but this CO criterion may lead many who have smoked within 24hr to be misclassified as abstinent.
Adult dependent smokers (N = 261; 124 men, 137 women) prospectively recorded each cigarette smoked and provided CO on five consecutive days during each of two short-term attempts to quit smoking. Participants were those recruited for crossover tests of the effects of placebo versus medication (nicotine patch or varenicline) on the ability to initiate 24-hr abstinence. All had either a high or low interest in permanently quitting smoking soon (within 3 months) and were randomized to the presence or absence of daily ($12) monetary reinforcement of abstinence.
Total accuracy of sensitivity to detect smoking (83%) plus specificity to verify abstinence (87%) was optimal at a CO criterion for abstinence below 5 ppm (≤4 ppm), compared with below 9 ppm (sensitivity of 60%, specificity of 97%). Overall CO detection of sensitivity and specificity was higher in those with high versus low quit interest, but reinforcement of abstinence made no difference.
Results indicate a CO criterion half that used in most clinical research may optimally validate 24-hr cessation and reduce misclassification of smokers as "abstinent."
通常通过呼气中一氧化碳（CO）水平低于 9 ppm（即≤8 ppm）来生化验证戒烟，但这一 CO 标准可能会导致许多在 24 小时内吸烟的人被错误分类为戒烟者。
成年有依赖性的吸烟者（N=261；124 名男性，137 名女性）前瞻性地记录每支吸烟的香烟，并在两次短期戒烟尝试中的每五天连续五次提供 CO。参与者是那些被招募来进行安慰剂与药物（尼古丁贴片或伐伦克林）对开始 24 小时戒烟能力影响的交叉测试的人。所有人都对尽快（在 3 个月内）永久性戒烟有较高或较低的兴趣，并随机分配到是否有每天（$12）的金钱奖励来促进戒烟。
在 CO 戒烟标准低于 5 ppm（≤4 ppm）时，检测吸烟的敏感性（83%）加上验证戒烟的特异性（87%）的总准确性最佳，而在 CO 戒烟标准低于 9 ppm 时（敏感性为 60%，特异性为 97%）。在那些戒烟兴趣较高的人群中，CO 的总体检测敏感性和特异性更高，但戒烟的强化并没有影响。
结果表明，与大多数临床研究中使用的标准相比，CO 标准降低一半可能最佳地验证了 24 小时的戒烟，并减少了将吸烟者错误分类为“戒烟者”的情况。
