Department for Forensic Psychiatry, University Hospital of Psychiatry.
Department of Statistics, Ludwig-Maximilians-Universität.
Psychol Assess. 2018 Apr;30(4):556-560. doi: 10.1037/pas0000524. Epub 2017 Oct 19.
Psychiatric and psychological diagnoses are imperfect. Unlike somatic medicine, most psychological and psychiatric phenomena have no gold standard to establish their presence beyond reasonable doubt. Consequently, prevalence estimates are based on the average agreement of imperfect evaluators. Küchenhoff, Augustin, and Kunz (2012) provided a statistical method for estimating confidence intervals of the prevalence based on the well-known kappa coefficient of interrater agreement. We expand this method and derive confidence intervals for the probability of a diagnosis being true (i.e., the positive predictive value). We illustrate the method and its results with empirical data for a particular type of paraphilia (pedophilia) in sexual offenders. The findings indicate that up to 1 in 3 diagnoses of pedophilia may be wrong. Given the similar rates of prevalence and interrater agreement reported for diagnoses in general psychiatry (such as schizophrenia or affective disorders), the results likely apply to other diagnostic domains as well. (PsycINFO Database Record
精神科和心理学诊断并不完美。与躯体医学不同，大多数心理和精神现象都没有金标准来确定其存在，除非有合理的怀疑。因此，患病率估计值基于不完美评估者的平均一致性。Küchenhoff、Augustin 和 Kunz（2012 年）提供了一种基于著名的评估者间kappa 一致性系数来估计患病率置信区间的统计方法。我们扩展了这种方法，并推导出了诊断为真的概率（即阳性预测值）的置信区间。我们用性犯罪者特定类型的性僻症（恋童癖）的实证数据来说明这种方法及其结果。研究结果表明，多达 1/3 的恋童癖诊断可能是错误的。鉴于一般精神病学（如精神分裂症或情感障碍）中报告的患病率和评估者间一致性率相似，这些结果可能也适用于其他诊断领域。
