Aims:To determine the quality of prospectively collected data from the highly specialized Danish Cerebral Palsy Follow-up Program (CPOP), and to establish the validity of a reported cerebral palsy (CP) diagnosis in the Danish National Patient Registry (NPR), regularly used as a proxy for neurodevelopmental disorders in epidemiological research.Methods:We compared data from the two registries on children with registered CP, born in Denmark between 2008 and 2009, with information from medical records verified by two experienced physicians specializing in pediatric neurology. Data accuracy was estimated by completeness, correctness, and reliability. Completeness was calculated as the number of cases with correctly registered CP diagnoses divided by the total number of true CP diagnoses (similar to sensitivity). Correctness was calculated as the number of cases with correct registrations divided by the total number of cases (similar to positive predictive value). Reliability was estimated using kappa statistics.Results:Registered CP diagnoses in the CPOP had high accuracy, with 94% correctness and 91% completeness. Furthermore, most key variables in the CPOP showed excellent reliability, especially variables defining the severity of the condition. In the Danish NPR, only 225 of 348 children with a noted CP diagnosis fulfilled the diagnostic criteria for CP, resulting in 65% correctness.Conclusions:Danish CPOP data are a valid source for epidemiological research. Conversely, a noted CP diagnosis in the Danish NPR was, at best, correct in only two out of three patients.

中文翻译：

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丹麦两个国家登记处的脑瘫诊断：一项验证研究

目的：确定高度专业化的丹麦脑瘫随访计划 (CPOP) 前瞻性收集的数据的质量，并定期确定丹麦国家患者登记处 (NPR) 中报告的脑瘫 (CP) 诊断的有效性方法：我们比较了两个登记处 2008 年至 2009 年出生于丹麦的 CP 儿童的数据，以及由两位经验丰富的儿科神经病学专家核实的医疗记录中的信息。数据准确性通过完整性、正确性和可靠性来评估。完整性的计算方法为正确登记 CP 诊断的病例数除以真实 CP 诊断的总数（类似于敏感性）。正确性的计算方法为正确登记的病例数除以病例总数（类似于阳性预测值）。使用kappa统计估计可靠性。结果：CPOP中注册的CP诊断具有很高的准确性，正确性为94%，完整性为91%。此外，CPOP 中的大多数关键变量都显示出出色的可靠性，尤其是定义病情严重程度的变量。在丹麦 NPR 中，348 名患有 CP 诊断的儿童中，只有 225 名符合 CP 的诊断标准，正确率为 65%。结论：丹麦 CPOP 数据是流行病学研究的有效来源。相反，丹麦 NPR 中著名的 CP 诊断充其量只有三分之二的患者是正确的。