van Leeuwen F E, van Duijn C M, Camps M H, Kempers B A, Mentjens M F, Mulder H B, Schouten E G, Zwijsen R M, Rookus M A
Department of Epidemiology, The Netherlands Cancer Institute, Amsterdam.
Contraception. 1992 May;45(5):399-408. doi: 10.1016/0010-7824(92)90154-l.
Case-control studies examining the effects of oral contraceptives (OC) are prone to misclassification bias due to errors in assessment of OC use. Concern about inaccurate exposure histories has increased since current studies require women to recall OC use over prolonged periods of time. In preparation for a case-control study of breast cancer and OC use, an investigation was carried out to assess agreement between women's lifetime histories of OC use (covering a period of up to 20 years) and prescribers' records. OC histories were obtained during personal interview with 218 women who had used OC at some point in their lives (127 breast cancer patients, 91 controls). Recall was aided by an album with color photographs of all OC marketed in the Netherlands from 1962 onwards (n = 65), and a calendar that covered the women's life span from date of birth to menopause. The participants were asked for the names of all physicians who prescribed OC for them. The rate of response from the prescribers was high (94%), but only half of the forms provided useful information. Patient-prescriber agreement on brand names (including dosage) was 70%. About half of the women agreed with their prescribers on starting dates to within less than a year's difference. Approximately the same percentage of agreement was found for stopping dates. Multiple linear regression indicated that agreement on brand names and dates of usage was lower for women of low socioeconomic status, for healthy women (as compared to breast cancer patients) and for periods of pill use that had to be recalled from the more distant past. Agreement on total duration of use was high enough to permit testing of a moderately strong duration-response relationship in a case-control study.
由于口服避孕药（OC）使用情况评估存在误差，病例对照研究在考察OC的效果时容易出现错误分类偏差。鉴于当前研究要求女性回忆长时间内的OC使用情况，对暴露史不准确的担忧日益增加。为准备一项关于乳腺癌与OC使用的病例对照研究，开展了一项调查，以评估女性OC使用的终生史（涵盖长达20年的时间段）与开处方者记录之间的一致性。通过个人访谈从218名曾在生命中某个阶段使用过OC的女性（127名乳腺癌患者，91名对照）获取OC史。借助一本包含1962年起在荷兰上市的所有OC彩色照片的相册（n = 65）以及一本涵盖女性从出生日期到绝经的寿命跨度的日历来辅助回忆。询问参与者为她们开OC处方的所有医生的姓名。开处方者的回应率很高（94%），但只有一半的表格提供了有用信息。患者与开处方者在品牌名称（包括剂量）上的一致性为70%。约一半的女性与开处方者在开始日期上的差异在不到一年之内达成一致。停药日期的一致率大致相同。多元线性回归表明，社会经济地位低的女性、健康女性（与乳腺癌患者相比）以及需要从更久远过去回忆的服药时间段，在品牌名称和使用日期上的一致性较低。在使用总时长上的一致性足够高，能够在病例对照研究中检验适度强的时长 - 反应关系。
