Murray R P, Connett J E, Lauger G G, Voelker H T
Department of Internal Medicine, University of Manitoba, Winnipeg, Canada.
Am J Public Health. 1993 Sep;83(9):1251-7. doi: 10.2105/ajph.83.9.1251.
Sources of measurement error in assessing smoking status are examined.
The Lung Health Study, a randomized trial in 10 clinical centers, includes 3923 participants in a smoking cessation program and 1964 usual care participants. Smoking at first annual follow-up was assessed by salivary cotinine, expired air carbon monoxide, and self-report. Each of these measures is known to contain some error. Sensitivity and specificity were calculated by comparing a biochemical measure with self-report to produce an undifferentiated estimate of error. Classification error rates due to imprecision of the biochemical measures and to the error in self-report were estimated separately.
For cotinine compared with self-report, the sensitivity was 99.0% and the specificity 91.5%. For carbon monoxide compared with self-report, the sensitivity was 93.7% and the specificity 87.2%. The classification error attributed to self-report, estimated by comparing the results from intervention and control groups, was associated with the responses of 3% and 5% of participants, indicating a small but significant bias toward a socially desirable response.
In absolute terms in these data, both types of error were small.
研究评估吸烟状况时测量误差的来源。
肺部健康研究是一项在10个临床中心开展的随机试验，包括3923名参加戒烟计划的参与者和1964名接受常规护理的参与者。首次年度随访时的吸烟情况通过唾液可替宁、呼出气体一氧化碳和自我报告进行评估。已知这些测量方法均存在一定误差。通过将生化测量结果与自我报告进行比较来计算敏感性和特异性，以得出误差的无差异估计值。分别估计了由于生化测量不精确和自我报告误差导致的分类错误率。
与自我报告相比，可替宁的敏感性为99.0%，特异性为91.5%。与自我报告相比，一氧化碳的敏感性为93.7%，特异性为87.2%。通过比较干预组和对照组的结果估计，归因于自我报告的分类错误与3%和5%的参与者的回答有关，表明存在向社会期望回答的小但显著的偏差。
就这些数据的绝对值而言，两种误差都很小。
