Converting between the International Prostate Symptom Score (IPSS) and the Expanded Prostate Cancer Index Composite (EPIC) urinary subscales: modeling and external validation

Background: Prostate-related quality of life can be assessed with a variety of different questionnaires. The 50-item Expanded Prostate Cancer Index Composite (EPIC) and the International Prostate Symptom Score (IPSS) are two widely used options. The goal of this study was, therefore, to develop and validate a model that is able to convert between the EPIC and the IPSS to enable comparisons across different studies. 
Methods: Three hundred forty-seven consecutive patients who had previously received radiotherapy and surgery for prostate cancer at two institutions in Switzerland and Germany were contacted via mail and instructed to complete both questionnaires. The Swiss cohort was used to train and internally validate different machine learning models using fourfold cross-validation. The German cohort was used for external validation.
Results: Converting between the EPIC Urinary Irritative/Obstructive subscale and the IPSS using linear regressions resulted in mean absolute errors (MAEs) ..., , , # Converting between the International Prostate Symptom Score (IPSS) and the Expanded Prostate Cancer Index Composite (EPIC) urinary subscales: modeling and external validation

[https://doi.org/10.5061/dryad.v6wwpzh4b](https://doi.org/10.5061/dryad.v6wwpzh4b)

The study was conducted in radiation oncology departments at two institutions, the Cantonal Hospital Winterthur in Switzerland and the Ruppiner Kliniken GmbH in Germany.

Three hundred and forty-seven consecutive patients who had received radiation therapy for prostate cancer in the post-operative setting at our institutions between 2010 and 2020 were identified and received the German versions of the EPIC and IPSS questionnaires in August 2020, unless a date of death had been documented in our electronic health records. Patients completed the questionnaires based on their current quality of life and symptom burden.

We received responses from 208 patients. Of these responses, 175 had no missing values for any of the quality of l...

背景：前列腺相关生活质量可通过多种不同问卷进行评估。50条目版前列腺癌综合指数量表（Expanded Prostate Cancer Index Composite, EPIC）与国际前列腺症状评分（International Prostate Symptom Score, IPSS）是两类广泛应用的评估工具。因此本研究旨在开发并验证一种可实现EPIC与IPSS间相互转换的模型，以支持不同研究间的结果对比。
方法：本研究通过邮件联系了347名曾在瑞士与德国两家医疗机构接受前列腺癌术后放疗与手术治疗的连续入组患者，要求其完成上述两份问卷。瑞士队列被用于训练不同机器学习模型，并通过四折交叉验证进行内部验证；德国队列则用于外部验证。
结果：通过线性回归实现EPIC泌尿刺激/梗阻亚量表与IPSS间的转换时，平均绝对误差（mean absolute errors, MAEs）……
# 国际前列腺症状评分（IPSS）与前列腺癌综合指数量表（EPIC）泌尿亚量表间的转换：建模与外部验证
[https://doi.org/10.5061/dryad.v6wwpzh4b](https://doi.org/10.5061/dryad.v6wwpzh4b)
本研究的开展机构为瑞士温特图尔州立医院与德国鲁平纳诊所股份公司的放射肿瘤科。
本研究纳入2010至2020年间在上述机构接受前列腺癌术后放疗的347名连续患者，于2020年8月向其发放EPIC与IPSS问卷的德语版本，除非患者的电子健康记录中已记录死亡日期。患者基于自身当前的生活质量与症状负荷完成问卷。
本研究共回收208份有效问卷，其中175份的所有生活质量相关条目均无缺失……