Department of Psychiatry, Pomeranian Medical University, Szczecin, Poland.
Division of Consultation Psychiatry and Neuroscience, Department of Psychiatry, Wroclaw Medical University, Wroclaw, Poland.
Psychopathology. 2023;56(6):453-461. doi: 10.1159/000529244. Epub 2023 Mar 6.
Psychometric properties of the Self-evaluation of Negative Symptoms (SNS) in subjects with the deficit subtype of schizophrenia (SCZ-D) have not been investigated so far. This study had the following aims: (1) to assess psychometric properties of SNS in subjects with SCZ-D and (2) to explore the usefulness of SNS, in comparison with other clinical characteristics, in screening for SCZ-D.
Participants were 82 stable outpatients with schizophrenia, including 40 individuals with SCZ-D and 42 individuals with the non-deficit subtype (SCZ-ND).
Internal consistency was acceptable-to-good in both groups. Factor analysis revealed two dimensions (apathy and emotional). There were significant positive correlations of the SNS total score with the subscore of negative symptoms from the Positive and Negative Syndrome Scale (PANSS) and significant negative correlations with scores of the Social and Occupational Functioning Assessment Scale (SOFAS) in both groups, indicating good convergent validity. The following measures were found to be appropriate screening tools for differentiating SCZ-D and SCZ-ND (p < 0.001): the SNS total score (area under the curve [AUC]: 0.849, cut-off ≥16, sensitivity: 80.0%, specificity: 78.6%), the PANSS subscore of negative symptoms (AUC: 0.868, cut-off ≥11, sensitivity: 90.0%, specificity: 78.6%), and the SOFAS (AUC: 0.779, cut-off ≤59, sensitivity: 69.2%, specificity: 82.5%). Also, adding the SOFAS (cut-off ≤59) to the SNS (cut-off: ≥16) further improved sensitivity and specificity (AUC: 0.898, p < 0.001, sensitivity = 87.5%, specificity = 82.2%). Cognitive performance and age of psychosis onset were not found to be suitable measures for differentiating SCZ-D and SCZ-ND.
The present findings indicate that the SNS has good psychometric properties in subjects with SCZ-D and those with SCZ-ND. Moreover, the SNS, the PANSS, and the SOFAS might be used as screening tools for SCZ-D.
目前尚未研究缺陷型精神分裂症（SCZ-D）患者的自我评估阴性症状量表（SNS）的心理测量特性。本研究的目的如下：（1）评估 SNS 在 SCZ-D 患者中的心理测量特性；（2）比较 SNS 与其他临床特征，探索其在筛查 SCZ-D 中的作用。
研究纳入 82 例稳定的精神分裂症门诊患者，其中 40 例为 SCZ-D 患者，42 例为非缺陷型（SCZ-ND）患者。
两组的内部一致性均为可接受至良好。因子分析显示 SNS 有两个维度（淡漠和情感）。在两组中，SNS 总分与阳性和阴性症状量表（PANSS）的阴性症状分量表得分呈显著正相关，与社会和职业功能评估量表（SOFAS）得分呈显著负相关，表明具有良好的聚合效度。以下指标被认为是区分 SCZ-D 和 SCZ-ND 的合适筛查工具（p < 0.001）：SNS 总分（曲线下面积[AUC]：0.849，截断值≥16，灵敏度：80.0%，特异性：78.6%）、PANSS 阴性症状分量表得分（AUC：0.868，截断值≥11，灵敏度：90.0%，特异性：78.6%）和 SOFAS（AUC：0.779，截断值≤59，灵敏度：69.2%，特异性：82.5%）。此外，将 SOFAS（截断值≤59）与 SNS（截断值：≥16）相结合，可进一步提高灵敏度和特异性（AUC：0.898，p < 0.001，灵敏度=87.5%，特异性=82.2%）。认知表现和精神病发病年龄均不适合作为区分 SCZ-D 和 SCZ-ND 的指标。
本研究结果表明，SNS 在 SCZ-D 患者和 SCZ-ND 患者中具有良好的心理测量特性。此外，SNS、PANSS 和 SOFAS 可作为 SCZ-D 的筛查工具。
