Cropsey Karen L, Eldridge Gloria D, Weaver Michael F, Villalobos Gabriela C, Stitzer Maxine L
Douglas Wilder School of Government and Public Affairs, Virginia Commonwealth University, Richmond, VA 23284, USA.
Nicotine Tob Res. 2006 Oct;8(5):653-9. doi: 10.1080/14622200600789684.
Breath carbon monoxide (CO) is a convenient, widely used method for abstinence validation, with cutoffs of 8-10 ppm commonly employed. The goal of the present study was to determine an appropriate CO cutoff to differentiate nonsmokers and smokers within a large sample (N = 374) of female prisoners incarcerated at a correctional facility in Virginia. Mean age of the population was 34.5 years, 49.2% were White, and 29% had less than a high school education. Smoking prevalence was 74.1% within the prison population. Examination of CO levels versus smoking self-report using a receiver operator characteristic (ROC) analysis revealed that a CO cutoff of 3 ppm resulted in the best sensitivity (98.1%) and specificity (95.8%). Overall ROC area under the curve was 99% (95% CI = 98.2%-99.9%). This same cutoff was optimal for smoking subgroups including Black and light (<10 cigarettes/day) smokers. Results suggest that CO cutoffs higher than 3 ppm may misclassify some smokers as nonsmokers and underestimate the prevalence of smoking.
呼出气一氧化碳（CO）是一种便捷且广泛应用于验证戒烟情况的方法，通常采用的截断值为8 - 10 ppm。本研究的目的是在弗吉尼亚州一所惩教设施中被监禁的大量女性囚犯样本（N = 374）中确定一个合适的CO截断值，以区分非吸烟者和吸烟者。该人群的平均年龄为34.5岁，49.2%为白人，29%的人受教育程度低于高中。监狱人群中的吸烟率为74.1%。使用受试者工作特征（ROC）分析来检验CO水平与吸烟自我报告之间的关系，结果显示，CO截断值为3 ppm时，敏感性最佳（98.1%），特异性最佳（95.8%）。曲线下的总体ROC面积为99%（95% CI = 98.2% - 99.9%）。对于包括黑人吸烟者和轻度吸烟者（每天<10支香烟）在内的吸烟亚组，这个相同的截断值也是最佳的。结果表明，高于3 ppm的CO截断值可能会将一些吸烟者误分类为非吸烟者，并低估吸烟率。
