pubmed:abstractText |
Within a case-control study of the relationship between oral contraceptives and breast cancer, information on other contraceptive practices, including use of an intrauterine device (IUD) was obtained through interviews of study subjects and from the records of gynaecologists. Information from these two sources was compared for 239 women who had ever used an IUD. The results showed that agreement on total duration, number of IUD episodes, and time since first and time since last IUD use was excellent. As approximately 75% of IUDs used were unknown, agreement on brands could not be investigated. Studies investigating the effects of individual types of IUDs should use physician records as an additional source of information.
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