Hunault Claudine C, Laven Joop S E, van Rooij Ilse A J, Eijkemans Marinus J C, te Velde Egbert R, Habbema J Dik F
Department of Public Health, Division of Reproductive Medicine, Erasmus MC University Medical Center Rotterdam, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
Hum Reprod. 2005 Jun;20(6):1636-41. doi: 10.1093/humrep/deh821. Epub 2005 Mar 10.
Models predicting clinical outcome need external validation before they can be applied safely in daily practice. This study aimed to validate two models for the prediction of the chance of treatment-independent pregnancy leading to live birth among subfertile couples.
The first model uses the woman's age, duration and type of subfertility, percentage of progressive sperm motility and referral status. The second model in addition uses the result of the post-coital test (PCT). For validation, these characteristics were collected prospectively in two University hospitals for 302 couples consulting for subfertility. The models' ability to distinguish between women who became pregnant and women who did not (discrimination) and the agreement between predicted and observed probabilities of treatment-independent pregnancy (calibration) were assessed.
The discrimination of both models was slightly lower in the validation sample than in the original sample which provided the model. Calibration was good: the observed and predicted probabilities of treatment-independent pregnancy leading to live birth did not differ for both models.
The chance of pregnancy leading to live birth was reliably estimated in the validation sample by both models. The use of PCT improved the discrimination of the models. These models can be useful in counselling subfertile couples.
预测临床结果的模型在能够安全应用于日常实践之前需要进行外部验证。本研究旨在验证两个用于预测不育夫妇中无需治疗而怀孕并活产几率的模型。
第一个模型使用女性年龄、不育的持续时间和类型、进行性精子活力百分比以及转诊状态。第二个模型还使用性交后试验（PCT）的结果。为了进行验证，前瞻性地收集了两家大学医院中302对因不育前来咨询的夫妇的这些特征。评估了模型区分怀孕女性和未怀孕女性的能力（辨别力）以及预测的和观察到的无需治疗而怀孕的概率之间的一致性（校准）。
验证样本中两个模型的辨别力均略低于提供模型的原始样本。校准良好：两个模型中观察到的和预测的无需治疗而怀孕并活产的概率没有差异。
在验证样本中，两个模型都能可靠地估计怀孕并活产的几率。PCT的使用提高了模型的辨别力。这些模型在为不育夫妇提供咨询时可能会有用。
