Neuropsychiatric Disease and Treatment (Dec 2019)

Pilot Validation Study of the Japanese Translation of the Brief Negative Symptoms Scale (BNSS)

  • Hashimoto N,
  • Toyomaki A,
  • Oka M,
  • Takanobu K,
  • Okubo R,
  • Narita H,
  • Kitagawa K,
  • Udo N,
  • Maeda T,
  • Watanabe S,
  • Oyanagi Y,
  • Miyazaki A,
  • Ito K,
  • Kusumi I

Journal volume & issue
Vol. Volume 15
pp. 3511 – 3518

Abstract

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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, JapanCorrespondence: Naoki HashimotoDepartment of Psychiatry, Hokkaido University Graduate School of Medicine, 060-8638 North 15, West 7, Sapporo, JapanTel +81-11-706-5160Fax +81-11-706-5081Email [email protected]: 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

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