Lindenmayer J P, Czobor Pal, Alphs Larry, Nathan Ann-Marie, Anand Ravi, Islam Zahur, Chou James C Y
New York University School of Medicine, New York, NY, USA.
Schizophr Res. 2003 Sep 1;63(1-2):161-70. doi: 10.1016/s0920-9964(02)00335-3.
The InterSePT Scale for Suicidal Thinking (ISST) is a 12-item instrument for the assessment of current suicidal ideation in patients with schizophrenia and schizoaffective disorders. We report the psychometric characteristics of this new scale based on two studies.
In Study 1, 22 inpatients with schizophrenia and schizoaffective disorders, who had recently attempted suicide or engaged in suicidal ideation, were rated by three trained independent raters to examine interrater reliability. In Study 2, a total of 980 patients with schizophrenia or schizoaffective disorder with a history of suicidal ideation in the past 36 months were enrolled in a 2-year industry-sponsored suicide prevention study. At baseline, these patients were administered the ISST and the Clinical Global Impression Scale for Severity of Suicidality (CGI-SS) by the Principal Investigator (PI) and by a blinded rater (BR), who also administered the Positive and Negative Symptom Scale (PANSS), the Calgary Depression Scale (CDS), and the Scale of Functioning (SOF). Indices of internal reliability, construct and discriminant validity were examined.
The intraclass correlation coefficient (ICC) for the total ISST score for the 22 subjects in Study 1 was 0.90 and mean weighted item kappa coefficients ranged from 0.66 to 0.92. In Study 2, internal reliability (Cronbach alpha) was high, ranging from 0.86 to 0.89 for the individual items, and the overall Cronbach alpha coefficient for all items was 0.88. The ISST (PI) total score was highly correlated with the CGI-SS by the blind rater (r = 0.61, p < 0.0001). ISST total scores significantly differentiated the different levels of CGI-SS (F = 519.2; p < 0.0001). Results of construct and discriminant validity analyses are also presented.
The ISST is a reliable and valid instrument for the assessment of current suicidal thinking in patients with schizophrenia and schizoaffective disorder by both clinicians and researchers.
自杀思维的InterSePT量表（ISST）是一种用于评估精神分裂症和分裂情感性障碍患者当前自杀意念的12项工具。我们基于两项研究报告了这一新量表的心理测量学特征。
在研究1中，22名近期有自杀未遂或自杀意念的精神分裂症和分裂情感性障碍住院患者由三名经过培训的独立评估者进行评分，以检验评估者间的信度。在研究2中，共有980名在过去36个月中有自杀意念史的精神分裂症或分裂情感性障碍患者参与了一项为期2年的由行业资助的自杀预防研究。在基线时，由主要研究者（PI）和一名盲法评估者（BR）对这些患者进行ISST和自杀严重程度临床总体印象量表（CGI-SS）评估，盲法评估者还进行了阳性和阴性症状量表（PANSS）、卡尔加里抑郁量表（CDS）以及功能量表（SOF）的评估。检验了内部信度、结构效度和区分效度指标。
研究1中22名受试者的ISST总分的组内相关系数（ICC）为0.90，平均加权项目kappa系数范围为0.66至0.92。在研究2中，内部信度（克朗巴哈α系数）较高，单个项目的克朗巴哈α系数范围为0.86至0.89，所有项目的总体克朗巴哈α系数为0.88。ISST（PI）总分与盲法评估者的CGI-SS高度相关（r = 0.61，p < 0.0001）。ISST总分显著区分了不同水平的CGI-SS（F = 519.2；p < 0.0001）。还呈现了结构效度和区分效度分析的结果。
ISST是临床医生和研究人员评估精神分裂症和分裂情感性障碍患者当前自杀思维的可靠且有效的工具。
