OBJECTIVE Youth with subthreshold mania are at increased risk of conversion to bipolar disorder (BP) I/II. Predictors for conversion have been published for the group as a whole. However, risk factors are heterogeneous, indicating the need for personalized risk assessment. METHOD One hundred forty youth with BP not otherwise specified (BP-NOS; 6-17 years old) followed through the Course and Outcome of Bipolar Youth (COBY) study with at least 1 follow-up assessment before conversion to BP-I/II were included. Youths were assessed on average every 7 months (median 11.5 years) using standard instruments. Risk predictors reported in the literature were used to build a 5-year risk calculator. Discrimination was measured using the time-dependent area under the curve after 1,000 bootstrap resamples. Calibration was evaluated by comparing observed with predicted probability of conversion. External validation was performed using an independent sample of 58 youths with BP-NOS recruited from the Pittsburgh Bipolar Offspring Study. RESULTS Seventy-five (53.6%) COBY youths with BP-NOS converted to BP-I/II, of which 57 (76.0%) converted within 5 years. Earlier-onset BP-NOS, familial hypomania/mania, and high mania, anxiety, and mood lability symptoms were important predictors of conversion. The calculator showed excellent consistency between the predicted and observed risks of conversion, good discrimination between converters and non-converters (area under the curve 0.71, CI 0.67-0.74), and a proportionally increasing rate of converters at each successive risk class. Discrimination in the external validation sample was good (area under the curve 0.75). CONCLUSION If replicated, the risk calculator would provide a useful tool to predict personalized risk of conversion from subsyndromal mania to BP-I/II and inform individualized interventions and research.

中文翻译：

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一种风险计算器，用于预测青少年从阈下双相情感障碍转变为双相情感障碍 I 或 II 的个体风险。

目标 患有阈下躁狂症的青少年转变为双相情感障碍 (BP) I/II 的风险增加。已为整个组发布了转换预测变量。然而，风险因素是异质的，表明需要进行个性化的风险评估。方法 140 名 BP 未特别指明的青年（BP-NOS；6-17 岁）在转换为 BP-I/II 之前至少进行了 1 次后续评估，并完成了双相青年的课程和结果 (COBY) 研究被包括在内。使用标准仪器平均每 7 个月（中位数 11.5 岁）对青少年进行一次评估。文献中报告的风险预测因子用于构建 5 年风险计算器。在 1,000 次 bootstrap 重采样后，使用曲线下的时间相关面积来测量辨别力。通过将观察到的转化概率与预测的转化概率进行比较来评估校准。外部验证是使用从匹兹堡双极后代研究中招募的 58 名患有 BP-NOS 的年轻人的独立样本进行的。结果 75 名 (53.6%) 患有 BP-NOS 的 COBY 青少年转变为 BP-I/II，其中 57 名 (76.0%) 在 5 年内转变。早发性 BP-NOS、家族性轻躁狂/躁狂、高度躁狂、焦虑和情绪不稳定症状是转化的重要预测因素。该计算器显示了预测和观察到的转化风险之间极好的一致性，转化者和非转化者之间的良好区分（曲线下面积 0.71，CI 0.67-0.74），以及每个连续风险类别中转化者的比例增加。外部验证样本的区分度很好（曲线下面积为 0.75）。结论 如果被复制，风险计算器将提供有用的工具来预测从亚综合征躁狂症转换为 BP-I/II 的个性化风险，并为个性化干预和研究提供信息。