Ades A E, Price M J, Kounali D, Akande V A, Wills G S, McClure M O, Muir P, Horner P J
Am J Epidemiol. 2017 Jan 15;185(2):124-134. doi: 10.1093/aje/kww117. Epub 2017 Jan 6.
In this study, we examined whether the proportion of tubal factor infertility (TFI) that is attributable to Chlamydia trachomatis, the population excess fraction (PEF), can be estimated from serological data using finite mixture modeling. Whole-cell inclusion immunofluorescence serum antibody titers were recorded among infertile women seen at St. Michael's Hospital in Bristol, United Kingdom, during the period 1985-1995. Women were classified as TFI cases or controls based on laparoscopic examination. Finite mixture models were used to identify the number of component titer distributions and the proportion of serum samples in each, from which estimates of PEF were derived. Four titer distributions were identified. The component at the highest titer was found only in samples from women with TFI, but there was also an excess of the second-highest titer component in TFI cases. Minimum and maximum estimates of the PEF were 28.0% (95% credible interval: 6.9, 50.0) and 46.8% (95% credible interval: 23.2, 64.1). Equivalent estimates based on the standard PEF formula from case-control studies were 0% and over 65%. Finite mixture modeling can be applied to serological data to obtain estimates of the proportion of reproductive damage attributable to C. trachomatis Further studies using modern assays in contemporary, representative populations should be undertaken.
在本研究中，我们探讨了能否使用有限混合模型从血清学数据中估算出由沙眼衣原体导致的输卵管因素不孕症（TFI）所占比例，即人群超额分数（PEF）。记录了1985年至1995年期间在英国布里斯托尔圣迈克尔医院就诊的不孕女性的全细胞包涵体免疫荧光血清抗体滴度。根据腹腔镜检查将女性分为TFI病例或对照。使用有限混合模型来确定成分滴度分布的数量以及每个分布中血清样本的比例，由此得出PEF的估计值。确定了四种滴度分布。发现最高滴度的成分仅存在于TFI女性的样本中，但TFI病例中第二高滴度成分也有超额。PEF的最小和最大估计值分别为28.0%（95%可信区间：6.9，50.0）和46.8%（95%可信区间：23.2，64.1）。基于病例对照研究的标准PEF公式得出的等效估计值为0%和超过65%。有限混合模型可应用于血清学数据，以获得由沙眼衣原体导致的生殖损害比例的估计值。应使用现代检测方法在当代代表性人群中开展进一步研究。
