Assessing Actigraphy-Determined Movement Variability as a Novel Objective Marker of Suicidal Ideation and Behavior Risk in Veterans and Its Role in Integrated Suicide Risk Assessment

 描述（由申请人提供）： 背景和目的：预防自杀是VHA的首要任务。每个卫生系统的自杀预防都受到难以预测自杀行为风险的阻碍，这是由于低基础率导致非常低的阳性预测值。最近，机器学习回归树方法成功地更好地识别了一组从军队医院出院后自杀风险特别高的人群。这一进步是非常必要的，因为出院后的头几个月到一年一再被证明是已知的自杀风险最高的时期之一。然而，出院后（以及任何其他时间）的自杀和自杀行为风险预测仍然极具挑战性。例如，这项研究的主要研究者发现，在相对较近的过去，绝大多数（73%）的VHA 抑郁症患者否认自杀意念，即使在自杀死亡后7天内被询问也是如此。显然需要制定不严重依赖患者自我报告的自杀行为风险衡量标准。最近，我们的合作研究者对非退伍军人住院患者的运动数据进行了非线性动态分析，并确定了一个与自杀意念相关性比任何其他特征更强的信号。研究设计：将对115-300名退伍军人进行一项前瞻性队列研究，以确定先前确定的与非退伍军人自杀意念高度相关的特定腕动记录测量值是否可预测退伍军人的自杀意念、自杀行为和/或再住院治疗。方法：将对115-300名在马萨诸塞州的贝德福德VAMC急性精神病科住院的退伍军人进行分析。主要分析将集中在75-200名目前有自杀想法或最近有自杀行为（SI/SB）的退伍军人身上，他们没有原发性精神病、阿尔茨海默病或帕金森病，也没有进行酒精解毒。将对40-100名接受酒精解毒的患者进行单独分析，其中一半患有SI/SB，一半没有SI/SB。 在他们的非优势手腕上安装小的、不显眼的、手表状活动记录仪，并完成自杀意念的自我评定和临床医生评定评估，以及其他精神症状严重程度的自我评定评估。将使用6分钟-2小时时间范围内运动幅度的非线性动态分析计算弹性指数（RI）。这些时间范围是运动数据的清晰结构明显的时期，有自杀意念的患者显示出比无自杀意念的患者更少的幅度变化。如果确定用于酒精解毒的药物不会干扰RI，则二次分析将检查115-300名退伍军人的整个样本。一个目标将侧重于确定原始弹性指数或替代运动数据指数（例如基于住院期间运动数据变化的指数）是否可预测退伍军人住院患者中自杀意念的存在和严重程度。这一目标还将检查RI检测任何自杀意念和实质性自杀意念存在的灵敏度和特异性。(In对于非退伍军人，RI检测任何自杀意念的敏感性为72%，特异性为100%，检测实质性意念的敏感性为86%，特异性为88%。第二个目标将确定RI是否预测出院后1个月、4个月或1年内的后续自杀行为或再住院，单独或结合症状严重程度、既往病史和当前住院的数据。影响：这项研究将大大有助于VHA的高优先级的努力，以减少自杀和自杀行为的退伍军人。这里研究的方法可能对自杀行为风险评估具有特殊价值，因为它不依赖于患者自我报告的症状。这项研究得到了VHA自杀预防计划的大力支持，认为这是一种单独或与其他现成信息结合进行自杀行为风险评估的新型且潜在高度有益的方法。

 DESCRIPTION (provided by applicant): BACKGROUND AND AIMS: Suicide prevention is a top VHA priority. Suicide prevention in every health system is hampered by difficulties with predicting the risk of suicidal behavior, due to low base rates leading to very low positive predictive values. Very recently, machine learning regression tree methods have succeeded in better identifying a group at particularly high risk of suicide post-discharge from military hospitals. This advance is greatly needed, since the first months to year post-discharge has been repeatedly shown to be one of the very highest-risk periods for suicide that is known. Nevertheless, suicide and suicidal behavior risk prediction post-discharge (and at any other time) is still extremely challenging. For instance, this study's Principal Investigator has found that, in the relatively recent past, a large majority (73%) of VHA patients with depression denied suicidal ideation even when asked within 7 days of their suicide death. A clear need exists to develop measures of suicidal behavior risk that are not heavily dependent on patient self-report. Recently, our Co-Investigators conducted nonlinear dynamic analysis of movement data from non-Veteran inpatients and identified a signal that was correlated more strongly to suicidal ideation than any other characteristic tested. RESEARCH DESIGN: A prospective cohort study of 115-300 Veterans will be conducted to determine if the previously-identified specific actigraphy-based measurements highly associated with suicidal ideation in non- Veterans will predict suicidal ideation, suicidal behavior, and/or rehospitalizatin in Veterans. METHODS: An analysis of 115-300 Veterans admitted to the Bedford, Massachusetts VAMC acute psychiatry unit will be conducted. The primary analysis will focus upon 75-200 Veterans with current suicidal ideation or recent suicidal behavior (SI/SB) who do not have a primary psychotic disorder, Alzheimer's, or Parkinson's disease, and who are not undergoing alcohol detoxification. A separate analysis will be conducted of 40-100 patients undergoing alcohol detoxification, half with SI/SB and half without SI/SB. Participants will wear a small, unobtrusive, wristwatch-like actigraph on their nondominant wrist, and complete self-rated and clinician- rated assessments of suicidal ideation, as well as self-rated assessments of the severity of other psychiatric symptoms. A Resiliency Index (RI) will be calculated using nonlinear dynamic analysis of the amplitude of movements over time frames from 6 minutes - 2 hours. These time frames are the periods for which a clear structure to the movement data is evident, with patients with suicidal ideation showing less variation in amplitude than patients without suicidal ideation. If medications given for alcohol detoxification are determined to not interfere with the RI, then a secondary analysis will examine the entire sample of 115-300 Veterans. One Aim will focus upon determining whether the original Resiliency Index or alternative movement data indices, such as one based on the change in the movement data over the hospitalization, predicts the presence and severity of suicidal ideation among Veteran inpatients. This aim will also examine the sensitivity and specificity of the RI for detecting the presence of any suicidal ideation, and of substantial suicidal ideation. (In non- Veterans, the RI showed a sensitivity of 72% and a specificity of 100% for detecting any suicidal ideation, and 86% and 88%, respectively, for detecting substantial ideation). The second Aim will determine whether the RI predicts subsequent suicidal behavior or rehospitalization over the next 1 month, 4 months, or 1 year after discharge, alone or combined with data about symptom severity, past history, and the present hospitalization. IMPACT: This study will contribute substantially to the VHA's high priority efforts to reduce suicide and suicidal behavior among Veterans. The approach studied here potentially likely particular value for suicidal behavior risk assessment in that it is not dependent on patient self-report of symptoms. This study is strongly supported by the VHA Suicide Prevention Program as a novel and potentially highly beneficial approach to suicidal behavior risk assessment, alone or combined with other readily available information.