Flaum M, Andreasen N
Mental Health Clinical Research Center, University of Iowa Hospitals and Clinics, Department of Psychiatry, University of Iowa College of Medicine, Iowa City 52242, USA.
Compr Psychiatry. 1995 Nov-Dec;36(6):421-7. doi: 10.1016/s0010-440x(95)90249-x.
The objective appearance of negative symptoms in schizophrenia and other psychotic disorders may be a direct reflection of a primary neural abnormality or may be secondary to a variety of factors such as neuroleptic side effects, depression, positive symptoms, or environmental understimulation. Although there is a consensus that it is important to be able to disentangle "primary" versus "secondary" negative symptoms, optimal strategies for doing so remain unclear. Concerns have been raised about making this distinction based on clinical judgment because of potential low reliability in the absence of extensive training and/or highly specialized rating scales. This is particularly important in terms of the application of DSM-IV criteria for schizophrenia, in which negative symptoms play a prominent role. In the context of the DSM-IV schizophrenia field trial project, we examined the reliability of making the primary versus secondary distinction in a multicenter sample of 462 subjects with nonorganic psychotic disorders. Each subject was assessed by two raters, half in an interrater design (i.e., conjoint interviews) and half in a test-retest design (i.e., independent interviews by two raters conducted 1 day apart). All raters used the same semistructured interview instrument, which included an abbreviated version of the Scale for the Assessment of Negative Symptoms (SANS). In addition to the usual SANS ratings, raters were asked to indicate their judgment as to whether the symptom was primary, secondary, or unknown (inadequate information to assess). No formal training was provided. Reliability, as quantified by kapp, indicated only a fair degree of agreement ranging from 0.48 to 0.68 for interrater reliability (median, 0.50) and 0.34 to 0.66 for test-retest reliability (median, 0.38). Negative symptoms were rated as primary approximately twice as often as secondary, and raters believed they had adequate information to make this distinction based only on cross-sectional evaluation in all but 10% of the cases. These data suggest that the primary versus secondary distinction should not be incorporated into the application of operationalized diagnostic criteria. Implications are discussed in terms of balancing reliability and validity in the assessment of negative symptoms.
精神分裂症和其他精神障碍中阴性症状的客观表现可能直接反映了原发性神经异常，也可能继发于多种因素，如抗精神病药物副作用、抑郁、阳性症状或环境刺激不足。尽管人们一致认为能够区分“原发性”与“继发性”阴性症状很重要，但实现这一目标的最佳策略仍不明确。由于在缺乏广泛培训和/或高度专业化评分量表的情况下，基于临床判断进行这种区分的可靠性可能较低，因此人们对此表示担忧。这在应用《精神疾病诊断与统计手册》第四版（DSM-IV）精神分裂症标准时尤为重要，其中阴性症状起着突出作用。在DSM-IV精神分裂症现场试验项目的背景下，我们在一个由462名非器质性精神障碍患者组成的多中心样本中，研究了区分原发性与继发性阴性症状的可靠性。每位受试者由两名评估者进行评估，其中一半采用评估者间设计（即联合访谈），另一半采用重测设计（即两名评估者在相隔1天的时间进行独立访谈）。所有评估者都使用相同的半结构化访谈工具，其中包括阴性症状评估量表（SANS）的简化版。除了常规的SANS评分外，评估者还被要求指出他们对症状是原发性、继发性还是未知（信息不足无法评估）的判断。未提供正式培训。用卡帕系数量化的可靠性表明，评估者间可靠性的一致性程度一般，范围为0.48至0.68（中位数为0.50），重测可靠性为0.34至0.66（中位数为0.38）。被评为原发性的阴性症状的频率约为继发性的两倍，并且评估者认为除了10%的病例外，他们仅基于横断面评估就有足够的信息进行这种区分。这些数据表明，原发性与继发性的区分不应纳入操作性诊断标准的应用中。本文将从平衡阴性症状评估中的可靠性和有效性的角度讨论其影响。
