BACKGROUND A self-harm episode is a major risk factor for repeat self-harm. Existing tools to assess and predict repeat self-harm have major methodological limitations, and few are externally validated. OBJECTIVE To develop and validate a risk assessment model of repeat self-harm up to 6 months after an episode of non-fatal self-harm that resulted in an emergency visit to hospital or specialised care. METHODS Using Swedish national registers, we identified 53 172 people aged≥10 years who self-harmed during 2008-2012. We allocated 37 523 individuals to development (2820 or 7.5% repeat self-harm incidents within 6 months) and 15 649 to geographic validation (1373 repeat episodes) samples, based on region of residence. In a temporal validation of people who self-harmed during 2018-2019, we identified 25 036 individuals (2886 repeat episodes). We fitted a multivariable accelerated failure time model to predict risk of repeat self-harm. FINDINGS In the external validations (n=40 685), rates of repeat self-harm were 8.8%-11.5% over 6 months. The final model retained 17 factors. Calibration and discrimination were similar in both validation samples, with observed-to-expected ratio=1.15 (95% CI=1.09 to 1.21) and c-statistic=0.72 (95% CI=0.70 to 0.73) in the geographical validation. At 6 months and a 10% risk cut-off, sensitivity was 51.5% (95% CI=48.8% to 54.2%) and specificity was 80.7% (95% CI=80.1% to 81.4%) in geographic validation; corresponding values were 56.9% (95% CI=55.1% to 58.7%) and 76.0% (95% CI=75.5% to 76.6%) in temporal validation. Discrimination was slightly worse at the 1-month prediction horizon (c-statistics of 0.66-0.68). CONCLUSIONS Using mostly routinely collected data, simple risk assessment models and tools can provide acceptable levels of accuracy for repeat of self-harm. CLINICAL IMPLICATIONS This risk model (OXford SElf-harm repeat tool) may assist clinical decision-making.

中文翻译：

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接受医疗保健服务的个人重复自我伤害的风险：临床风险评估模型 （OxSET） 的开发和验证。


背景 自我伤害发作是反复自我伤害的主要危险因素。现有的评估和预测重复自我伤害的工具存在重大的方法学局限性，而且很少有经过外部验证的。目的 开发和验证在非致命性自我伤害发作后 6 个月内重复自我伤害的风险评估模型，导致紧急就诊或专业护理。方法 使用瑞典国家登记册，我们确定了 53 172 名年龄≥ 10 岁的人在 2008-2012 年期间自残。我们根据居住地区将 37 523 人分配给发展 （2820 或 7.5% 在 6 个月内重复自残事件），将 15 649 人分配给地理验证 （1373 次重复事件） 样本。在对 2018-2019 年期间自残人群的时间验证中，我们确定了 25 036 人 （2886 次重复发作）。我们拟合了一个多变量加速失败时间模型来预测重复自我伤害的风险。结果 在外部验证 （n=40 685） 中，6 个月内重复自我伤害的发生率为 8.8%-11.5%。最终模型保留了 17 个因子。两个验证样本的校准和鉴别相似，在地理验证中，观察到与预期比率 = 1.15 （95% CI = 1.09 至 1.21） 和 c 统计量 = 0.72 （95% CI = 0.70 至 0.73）。在 6 个月和 10% 的风险临界值时，地理验证的敏感性为 51.5% （95% CI=48.8%， 54.2%），特异性为 80.7% （95% CI=80.1%， 81.4%）;在时间验证中，相应的值为 56.9% （95% CI=55.1% 至 58.7%） 和 76.0% （95% CI=75.5% 至 76.6%）。在 1 个月的预测范围内，辨别力略差 （c 统计量为 0.66-0.68）。 结论 使用大部分常规收集的数据，简单的风险评估模型和工具可以为重复自我伤害提供可接受的准确性水平。临床意义 该风险模型 （OXford SElf-harm repeat tool） 可能有助于临床决策。