Tekkel M Iu, Kolle Kh A
Vopr Onkol. 1986;32(2):53-6.
The quality of the data collected in a retrospective cohort breast cancer study in Estonia was evaluated. Two separate approaches were used to investigate possible biases in the study. Firstly, a similar questionnaire was mailed to a sample of 86 women twice during an interval of one week to six months. Overall questionnaire reliability was 83.4%. Secondly, comparisons of the data obtained by postal questionnaires about past history of lung tuberculosis with hospital medical record information revealed that 2.5% of women with severe forms of the disease and 30.3% with milder forms (controls) had denied their previous disease. These findings show that more attention must be paid to the quality control procedures in cancer epidemiology studies.
对爱沙尼亚一项回顾性队列乳腺癌研究中收集的数据质量进行了评估。采用了两种不同的方法来调查该研究中可能存在的偏差。首先，在一至六个月的间隔期内，向86名女性样本两次邮寄了类似的问卷。问卷总体可靠性为83.4%。其次，将通过邮政问卷获得的有关肺结核既往史的数据与医院病历信息进行比较，结果显示，患有严重形式疾病的女性中有2.5%以及病情较轻形式（对照组）的女性中有30.3%否认了她们之前的疾病。这些发现表明，在癌症流行病学研究中必须更加关注质量控制程序。
