This study examined the clinical utility of the Negative Symptom Assessment-16 (NSA-16) in schizophrenia. 274 individuals with schizophrenia were assessed on the NSA-16, Positive and Negative Syndrome Scale (PANSS), Clinical Assessment for Negative Symptoms (CAINS), Calgary Depression Scale for Schizophrenia (CDSS), Social and Occupational Functioning Assessment Scale (SOFAS) and the Simpson-Angus Extrapyramidal Side Effects Scale (SAS). Factor analyses were conducted and Cronbach's alpha was computed. Correlations were assessed using Spearman's correlation coefficient. The 5-factor model of the NSA-16 did not give good fit statistics from our sample. Exploratory factor analysis on a randomly selected split-half of the sample followed by confirmatory factor analysis on the remaining sample supported a 4-factor structure with 12 items. The factors were: Restricted speech, Poor quality of speech, Affective blunting and Amotivation. The NSA-16 with the 12 items was termed as the NSA-12. The NSA-12 showed good internal reliability. The NSA-12 total score and global negative symptom rating had strong correlations with CAINS total and PANSS negative factor scores, suggesting good convergent validity. Weak correlations of the NSA-12 total score and global negative symptom rating with PANSS positive, CDSS and SAS scores suggested good divergent validity. The NSA-12 total score and global negative symptom rating were strongly and inversely associated with SOFAS and positively associated with NSA-12 global level of functioning. In conclusion, the NSA-12 is useful to evaluate negative symptoms in clinical and research settings in individuals with schizophrenia. Our study results also support a 4-factor structure of the NSA-12 in outpatients with schizophrenia.

中文翻译：

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阴性症状评估-16 在精神分裂症患者中的临床效用

本研究检查了阴性症状评估 16 (NSA-16) 在精神分裂症中的临床效用。274 名精神分裂症患者接受了 NSA-16、阳性和阴性综合征量表 (PANSS)、阴性症状临床评估 (CAINS)、卡尔加里精神分裂症抑郁量表 (CDSS)、社会和职业功能评估量表 (SOFAS) 和辛普森-安格斯锥体外系副作用量表 (SAS)。进行了因子分析并计算了 Cronbach 的 alpha。使用斯皮尔曼相关系数评估相关性。NSA-16 的 5 因子模型没有从我们的样本中给出很好的拟合统计数据。对随机选择的一半样本进行探索性因素分析，然后对剩余样本进行验证性因素分析，支持 12 个项目的 4 因素结构。影响因素包括：言语受限、言语质量差、情感迟钝和缺乏动力。具有 12 个项目的 NSA-16 被称为 NSA-12。NSA-12 表现出良好的内部可靠性。NSA-12 总分和总体阴性症状评分与 CAINS 总分和 PANSS 阴性因素评分有很强的相关性，表明具有良好的收敛效度。NSA-12 总分和总体阴性症状评分与 PANSS 阳性、CDSS 和 SAS 分数的弱相关表明良好的发散效度。NSA-12 总分和总体阴性症状评分与 SOFAS 呈强烈负相关，与 NSA-12 总体功能水平呈正相关。总之，NSA-12 有助于评估精神分裂症患者在临床和研究环境中的阴性症状。