Christensen Anne E, Tobiassen Mette, Jensen Tina K, Wielandt Hanne, Bakketeig Leiv, Høst Arne
Department of Pediatrics, Odense University Hospital, Odense, Denmark.
Paediatr Perinat Epidemiol. 2004 Jan;18(1):73-9. doi: 10.1111/j.1365-3016.2003.00520.x.
Exposure to environmental tobacco smoke (ETS) during fetal life and infancy is closely related to the smoking habits of the parents. Estimates of exposure to ETS require valid and detailed information on changes in cigarette smoking over time. The objective was to test the validity of self-reported smoking among parents during pregnancy and early childhood in a cohort of children at high risk for allergy development by measurement of exhaled carbon monoxide (CO). The cohort comprised 117 families enrolled from the general population of pregnant women at admission to antenatal care. Data on parental tobacco smoking were obtained by interview and exhaled CO was measured (Micro-Smokerlyzer(R)) in parents twice during pregnancy and when the child was 6 and 18 months old. The median (range) exhaled CO levels were 3 (0-10) parts per million (ppm) for non-smokers and 15 (1-39) ppm for smokers (P < 0.0005). A receiver operating characteristic (ROC) analysis was performed at each examination. The areas under the ROC curve were high for both mothers (between 0.88 and 0.99) and fathers (between 0.87 and 0.89), indicating exhaled CO as a good diagnostic tool for determining smoking status. Comparing the ROC areas obtained for mothers from late pregnancy and during infancy with the area from early pregnancy showed no statistical differences (P = 0.21, 0.43 and 0.44 respectively) and the same was true for fathers during infancy (P = 0.81). The level of 8 ppm was used as the cut-off between smokers and non-smokers, based on data from a pilot study. Using CO as a diagnostic tool for smoker status showed very high specificity (between 97 and 100%), indicating that very few persons claiming to be non-smokers had CO levels higher than 8 ppm. In conclusion, the validity of interview-obtained self-reported smoking among parents during pregnancy and early childhood was high. Repeated interviews and CO measurements in a prospective study design did not change the validity, indicating a low risk of information bias. A structured interview combined with measurement of exhaled CO is a valid and reliable method for estimating ETS exposure to the fetus and young infant.
胎儿期和婴儿期暴露于环境烟草烟雾（ETS）与父母的吸烟习惯密切相关。对ETS暴露的估计需要关于吸烟随时间变化的有效且详细的信息。目的是通过测量呼出一氧化碳（CO）来检验在一组有过敏发展高风险儿童的队列中，父母在孕期和幼儿期自我报告吸烟情况的有效性。该队列由117个家庭组成，这些家庭是从接受产前护理的孕妇普通人群中招募的。通过访谈获取父母吸烟的数据，并在孕期两次以及孩子6个月和18个月大时，对父母测量呼出CO（使用Micro-Smokerlyzer(R)）。非吸烟者呼出CO水平的中位数（范围）为3（0 - 10）百万分率（ppm），吸烟者为15（1 - 39）ppm（P < 0.0005）。每次检查时均进行了受试者工作特征（ROC）分析。母亲（0.88至0.99之间）和父亲（0.87至0.89之间）的ROC曲线下面积都很高，表明呼出CO是确定吸烟状况的良好诊断工具。将母亲在妊娠晚期和婴儿期获得的ROC面积与妊娠早期的面积进行比较，未发现统计学差异（分别为P = 0.21、0.43和0.44），婴儿期父亲的情况也是如此（P = 0.81）。根据一项初步研究的数据，8 ppm的水平被用作吸烟者与非吸烟者的分界点。使用CO作为吸烟者状态的诊断工具显示出非常高的特异性（97%至100%之间），这表明自称非吸烟者中很少有人的CO水平高于8 ppm。总之，父母在孕期和幼儿期通过访谈获得的自我报告吸烟情况的有效性很高。在前瞻性研究设计中进行重复访谈和CO测量并没有改变有效性，表明信息偏倚风险较低。结构化访谈结合呼出CO测量是估计胎儿和幼儿ETS暴露的有效且可靠的方法。
