Achilles Sharon L, Mhlanga Felix G, Musara Petina, Poloyac Samuel M, Chirenje Zvavahera M, Hillier Sharon L
Department of Obstetrics, Gynecology, and Reproductive Sciences and Center for Family Planning Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Magee-Womens Research Institute, Pittsburgh, PA, USA.
University of Zimbabwe-University of California at San Francisco Collaborative Research Unit (UZ-UCSF), Department of Obstetrics and Gynecology, Harare, Zimbabwe.
Contraception. 2018 Apr;97(4):346-353. doi: 10.1016/j.contraception.2017.09.013. Epub 2017 Sep 28.
Researchers traditionally rely on participant self-report for contraceptive use. We hypothesized that self-reported contraceptive use by clinical research participants may disagree with objectively measured hormonal status.
We enrolled women in Harare, Zimbabwe, aged 18-34, who by self-report had not used hormonal or intrauterine contraception for >30 days, or depot medroxyprogesterone acetate for >10 months, into a study designed to assess biologic changes with contraceptive initiation and use. Blood samples obtained at enrollment and each follow-up visit (N=1630 from 447 participants) were evaluated by mass spectrometry for exogenous hormones. We individually interviewed a subset of participants (n=20) with discrepant self-reported and measured serum hormones to better understand nondisclosure of contraceptive use.
Discrepant with self-reported nonuse of hormonal contraception, synthetic progestogens were detectable in 120/447 (27%, 95% confidence interval 23%-31%) enrolled women. Measured exogenous hormones consistent with use of contraceptive pills (n=102), injectables (n=20) and implants (n=3) were detected at enrollment, with 7 women likely using >1 contraceptive. In-depth interviews revealed that participants understood the requirement to be hormone free at enrollment (100%). Most (85%) cited partner noncooperation with condoms/withdrawal and/or pregnancy concerns as major reasons for nondisclosed contraceptive use. All interviewed women (100%) cited access to health care as a primary motivation for study participation. Of participants who accurately reported nonuse of hormonal contraception at enrollment, 41/327 (12.5%) had objective evidence of nonstudy progestin use at follow-up that disagreed with self-reported nonuse.
Women joining contraceptive research studies may misrepresent their use of nonstudy contraceptive hormones at baseline and follow-up. Objective measures of hormone use are needed to ensure that study population exposures are accurately categorized.
Among Zimbabwean women participating in a contraceptive research study, 27% had objective evidence of use of nonstudy contraceptives at enrollment that disagreed with self-report. Studies that rely on self-report to identify contraceptive hormone exposure could suffer from significant misclassification.
研究人员传统上依赖参与者的自我报告来了解避孕措施的使用情况。我们推测，临床研究参与者自我报告的避孕措施使用情况可能与客观测量的激素状态不一致。
我们在津巴布韦哈拉雷招募了年龄在18至34岁之间的女性，这些女性自我报告称未使用激素或宫内避孕措施超过30天，或未使用醋酸甲羟孕酮长效避孕针超过10个月，将她们纳入一项旨在评估开始和使用避孕措施时生物学变化的研究。在入组时以及每次随访时采集的血样（来自447名参与者的1630份样本）通过质谱法检测外源激素。我们对自我报告的激素使用情况与检测到的血清激素情况存在差异的一部分参与者（n = 20）进行了单独访谈，以更好地了解未披露避孕措施使用情况的原因。
在447名入组女性中，有120名（27%，95%置信区间23% - 31%）检测到了合成孕激素，这与她们自我报告未使用激素避孕措施的情况不符。在入组时检测到了与使用避孕药（n = 102）、注射用避孕药（n = 20）和植入式避孕器（n = 3）相符的外源激素，有7名女性可能同时使用了不止一种避孕措施。深入访谈显示，参与者明白入组时需处于无激素状态（100%）。大多数人（85%）表示伴侣不配合使用避孕套/体外排精和/或担心怀孕是未披露避孕措施使用情况的主要原因。所有接受访谈的女性（100%）都表示获得医疗保健是参与研究的主要动机。在入组时准确报告未使用激素避孕措施的参与者中，有41/327（12.5%）在随访时有未参与研究的孕激素使用的客观证据，这与她们自我报告的未使用情况不符。
参与避孕研究的女性在基线和随访时可能会误报其未参与研究的避孕激素的使用情况。需要客观的激素使用测量方法来确保对研究人群的暴露情况进行准确分类。
在参与一项避孕研究的津巴布韦女性中，27%的人在入组时有未参与研究的避孕措施使用的客观证据，这与她们的自我报告不符。依赖自我报告来确定避孕激素暴露情况的研究可能会存在严重的分类错误。
