Drug-Induced Extrapyramidal Symptoms Scale of the Norwegian version: inter-rater and test–retest reliability

Abstract

Background: The Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) is a multidimensional rating scale designed for the fast, easy and reliable assessment of extrapyramidal symptoms (EPSs) induced by antipsychotics.

Aim: The aim of this study was to validate the level of inter-rater and test–retest reliability of the Norwegian translation of this scale.

Methods: A total of 125 video clips showing a variety of or no signs of EPSs were used in the present study. The participants recorded were Japanese psychiatric patients receiving first- and/or second-generation antipsychotics. A total of 103 patients (47 males and 56 females), diagnosed with schizophrenia (n = 68) or mood disorders (n = 35) appeared in the video clips. Their mean age was 48.7 ± 16.3 years (range 18–80) at the time of video recording. Inter-rater agreement was assessed with five raters and test–retest reliability with three.

Results: Inter-rater reliability analyses showed interclass correlation coefficients (ICCs) ranging from 0.74 to 0.93 for each individual item. Test–retest reliability analysed independently for each rater ranged from 0.71 to 0.96.

Conclusions: Inter-rater and test–retest agreement exhibited satisfactory ICC levels above 0.70. The Norwegian version of the DIEPSS is a reliable instrument for the assessment of drug-induced EPSs.

Keywords:

• DIEPPS
• extrapyramidal symptoms
• antipsychotics
• side effects
• reliability

Acknowledgements

We are grateful to all patients volunteering in the video clips. In addition, we wish to thank all researchers involved in the translation and validation of the DIEPSS: Kristina Albertsen, Ida Johnsen Steiro and Marit Elise Lien contributed to the translation work; Lucia Babiano-Espinosa and Kristin Ytreland contributed to the validation study.

Disclosure statement

The authors report no conflicts of interest.

Data availability statement

The Norwegian translation of the DIEPSS, including the user manual, is freely available for non-commercial clinical or research purposes upon request from the corresponding author or from the scale developer, Toshiya Inada (email: [email protected]). The data that support the findings of this study are available from the corresponding author upon request.

Additional information

Funding

This study was partly supported by the Research Grants-in-Aid for Scientific Research from the Ministry of Health, Labour and Welfare in Japan (1994, 1997, 1998, 2005) and the Ministry of Education, Culture, Sports, Science and Technology in Japan (1996), and the TroNa Collaborative Project between Norway and Japan.

Notes on contributors

Bernhard Weidle

Bernhard Weidle, MD, PhD, is a specialist in Pediatrics and Child and Adolescent Psychiatry, Associate Professor at the Regional Centre for Child and Youth Mental Health and Child Welfare, NTNU and senior consultant at the Department of Child and Adolescent Psychiatry, St. Olav's University Hospital, Trondheim, Norway.

Ashmita Chaulagain

Ashmita Chaulagain, Master of Public Health, is a research assistant at the Regional Centre for Child and Youth Mental Health and Child Welfare, NTNU, Trondheim, Norway. Her research interest are mental health and epidemiology.

Kenneth Stensen

Kenneth Stensen is a researcher at the Regional Centre for Child and Youth Mental Health and Child Welfare, NTNU, Trondheim, Norway. He has a master's degree in psychology with research areas developmental psychology and psychopathology and psychometry/validation of clinical measurement.

Branko Aleksic

Branko Aleksic, MD from Belgrade University, Serbia. PhD in Psychiatry/Psychobiology at Nagoya University, Japan, member of the Serbian Medical Society, Japanese Society for Biological Psychiatry, International Society of Psychiatric Genetics, Japanese Neuroscience Society and Japanese Society of Human Genetics. He is also an editorial board member of PLoS ONE and Scientific Reports.

Norbert Skokauskas

Norbert Skokauskas, MD, PhD, is Professor of Child and Adolescent Psychiatry and Chair for Research at the Regional Centre for Child and Youth Mental Health and Child Welfare, NTNU. He is the Chair of the World Psychiatric Association, Child and Adolescent Psychiatry section and the Editor of ‘World Child and Adolescent Psychiatry”.

Toshiya Inada

Toshiya Inada, MD, PhD, is an Associate Professor at the Department of Psychiatry and Psychobiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. He graduated from Keio University School of Medicine, Tokyo, Japan. His major research topics include clinical neuropsychopharmacology, especially antipsychotic-induced movement disorders.