Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, United Kingdom.
PLoS One. 2012;7(2):e31727. doi: 10.1371/journal.pone.0031727. Epub 2012 Feb 16.
Clinical guidelines recommend that violence risk be assessed in schizophrenia. Current approaches are resource-intensive as they employ detailed clinical assessments of dangerousness for most patients. An alternative approach would be to first screen out patients at very low risk of future violence prior to more costly and time-consuming assessments. In order to implement such a stepped strategy, we developed a simple tool to screen out individuals with schizophrenia at very low risk of violent offending. We merged high quality Swedish national registers containing information on psychiatric diagnoses, socio-demographic factors, and violent crime. A cohort of 13,806 individuals with hospital discharge diagnoses of schizophrenia was identified and followed for up to 33 years for violent crime. Cox regression was used to determine risk factors for violent crime and construct the screening tool, the predictive validity of which was measured using four outcome statistics. The instrument was calibrated on 6,903 participants and cross-validated using three independent replication samples of 2,301 participants each. Regression analyses resulted in a tool composed of five items: male sex, previous criminal conviction, young age at assessment, comorbid alcohol abuse, and comorbid drug abuse. At 5 years after discharge, the instrument had a negative predictive value of 0.99 (95% CI = 0.98-0.99), meaning that very few individuals who the tool screened out (n = 2,359 out of original sample of 6,903) were subsequently convicted of a violent offence. Screening out patients who are at very low risk of violence prior to more detailed clinical assessment may assist the risk assessment process in schizophrenia.
临床指南建议评估精神分裂症患者的暴力风险。目前的方法需要大量资源，因为它们对大多数患者进行详细的临床危险评估。另一种方法是在进行更昂贵和耗时的评估之前，首先筛选出未来暴力风险极低的患者。为了实施这种分阶段策略，我们开发了一种简单的工具，用于筛选出暴力犯罪风险极低的精神分裂症患者。我们合并了高质量的瑞典国家登记册，其中包含了关于精神科诊断、社会人口因素和暴力犯罪的信息。确定了一个包含 13806 名有住院精神分裂症诊断的队列，并对他们进行了长达 33 年的暴力犯罪随访。使用 Cox 回归来确定暴力犯罪的危险因素，并构建筛选工具，使用四个结果统计来衡量其预测有效性。该工具在 6903 名参与者中进行了校准，并使用 3 个独立的复制样本（每个样本包含 2301 名参与者）进行了交叉验证。回归分析得出了一个由五个项目组成的工具：男性、先前的刑事定罪、评估时的年轻年龄、合并酒精滥用和合并药物滥用。在出院后 5 年，该工具的阴性预测值为 0.99（95%CI=0.98-0.99），这意味着很少有工具筛选出的患者（6903 名原始样本中 n=2359 名）随后被判犯有暴力罪行。在进行更详细的临床评估之前，筛选出暴力风险极低的患者可能有助于精神分裂症的风险评估过程。
