Pilot Validation Study of the Japanese Translation of the Brief Negative Symptoms Scale (BNSS)
Received 5 November 2019
Accepted for publication 13 December 2019
Published 23 December 2019 Volume 2019:15 Pages 3511—3518
Checked for plagiarism Yes
Review by Single-blind
Peer reviewer comments 2
Editor who approved publication: Dr Taro Kishi
Naoki Hashimoto,1 Atsuhito Toyomaki,1 Matsuhiko Oka,1 Keisuke Takanobu,1 Ryo Okubo,2 Hisashi Narita,1 Kan Kitagawa,1 Niki Udo,1 Tamaki Maeda,1 Shinya Watanabe,1 Yuka Oyanagi,1 Akane Miyazaki,1 Koki Ito,1 Ichiro Kusumi1
1Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan; 2Department of Clinical Epidemiology, Translational Medical Center, National Center for Neurology and Psychiatry, Tokyo 187-8551, Japan
Correspondence: Naoki Hashimoto
Department of Psychiatry, Hokkaido University Graduate School of Medicine, 060-8638 North 15, West 7, Sapporo, Japan
Purpose: The brief negative symptoms scale (BNSS) is a concise instrument used to assess negative symptoms of subjects with schizophrenia covering five domains of negative symptoms and is suitable for use in clinical, experimental, and epidemiological settings. The original and translated version of BNSS has thus far been shown to have adequate psychometric properties. This study aimed to examine internal consistency, inter-rater and test-retest reliability, discriminant and convergent validity, and factor structure of the Japanese version of BNSS.
Patients and methods: The assessment was performed by 11 raters using interview videos of nine subjects. Reliability was calculated with Cronbach’s alpha for internal consistency and intra class correlation coefficient (ICC) for inter-rater reliability. Pearson’s correlation coefficients were calculated to estimate the test-retest reliability. In addition to BNSS, Scale for assessment of negative symptoms (SANS) and scale for assessment of positive symptoms (SAPS) was obtained to assess the convergent and discriminant validity. Factor structure was assessed using principle factor analysis.
Results: The Japanese BNSS showed excellent internal consistency (Cronbach’s alpha=0.95), inter-rater reliability (intra class correlation coefficient=0.97), and test-retest reliability (r=0.94, p<0.001). The convergent validity shown by correlation with SANS total score (r=0.87, p<0.001) and discriminant validity shown by correlation with SAPS total score (r=0.17, p=−0.68) were also good. Principal factor analysis revealed a two-factor structure of BNSS, although the loading of each item differed from that in the literature.
Conclusion: Our pilot study demonstrated that Japanese BNSS had good psychometric properties which were achieved with relatively brief training. Further studies with more subjects and raters with various backgrounds recruited from multiple sites are warranted.
Keywords: negative symptom, schizophrenia, scale, factor structure
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]