Development of a new benzodiazepine hypnotics withdrawal symptom scale
For prevention and early detection of dependence on hypnotics such as benzodiazepines (BZDs) or its agonists, a withdrawal symptom scale specialized for this kind of drug has long been sought. In this study, the benzodiazepine hypnotics withdrawal symptom scale (BHWSS) was developed using item response theory (IRT). This study enrolled 121 chronic insomnia patients (mean age 46.1 ± 15.6 years) who had been treated with hypnotics for 3 or more months. The patients were asked to fill a questionnaire that was developed by selecting questions from Benzodiazepine Withdrawal Symptom Questionnaire (BWSQ) and Clinical Institute Withdrawal Assessment for Benzodiazepines (CIWA-B) on the basis of the symptoms triggered by reduction or abrupt cessation of the intake of hypnotics. A factor analysis was performed to verify the assumption that the new scale had one dimension. We drew item response category characteristic curves, following the IRT. Besides statistical considerations, clinical implications were also incorporated to select the 12 items used to construct the BHWSS questionnaire. Using the analyses based on IRT, 6 items each were selected from BWSQ and CIWA-B. The cumulative proportion of contribution of the first factor, obtained by factor analysis, was found to be 0.36. Cronbach’s α coefficient and McDonald’s ω coefficient were calculated to be 0.86 and 0.87, respectively. The total score of 12 items increased monotonically with the increasing level of withdrawal symptoms. The BHWSS could potentially become a practical tool for estimating the degree of BZD withdrawal symptoms.
KeywordsInsomnia Benzodiazepine and benzodiazepine receptor agonist hypnotics Withdrawal symptom Self-checked questionnaire Item response theory Factor analysis
For creating of the new scale reported in this study, we obtained permission from Peter Tyrer (BWSQ) and Edward M. Sellers (CIWA-B) to use the questionnaire scales. The authors would like to offer special thanks to Shyun Nakajima, staff of Teikyo University, and Moeko Ochi, staff of Soshin Mental Care Clinic for recruitment and collecting data. We would like to thank Editage (http://www.editage.jp) for English language editing.
This research is supported by the “Health and Labor Sciences Research Grants for Comprehensive Research on Persons with Disabilities” from Japan Agency for Medical Research and Development, AMED and Intramural Research Grant (29-1) for Neurological and Psychiatric Disorders of NCNP.
Compliance with ethical standards
Conflict of interest
Takashi Kikuchi, a member of Translational Research Information Center, was consulted for statistical analysis but was not involved in writing the manuscript or collecting data. Other authors have no conflict of interest in this study.
All the procedures undertaken to perform experiments involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
Informed consent was obtained from all the participants included in this study.
- 1.American Academy of Sleep Medicine. International classification of sleep disorders, 3rd ed. Darien: American Academy of Sleep Medicine; 2014.Google Scholar
- 10.Murakoshi A, Takaesu Y, Komada Y, Ishikawa J, Inoue Y. Prevalence and associated factors of hypnotics dependence among Japanese outpatients with psychiatric disorders. Psychiatry Res. 2015; 230:958–963.Google Scholar
- 17.American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. American Psychiatric Association, Arlington; 2013.Google Scholar
- 22.Christine DeMars. Item response theory (understanding statistics). Oxford University Press, New York; 2010 ISBN-13:978-0195377033.Google Scholar
- 27.Wade AG, Ford I, Crawford G, McConnachie A, Nir T, Laudon M, Zisapel N. Nightly treatment of primary insomnia with prolonged release melatonin for 6 months: a randomized placebo controlled trial on age and endogenous melatonin as predictors of efficacy and safety. BMC Med. 2010;8:51. https://doi.org/10.1186/1741-7015-8-51.CrossRefPubMedPubMedCentralGoogle Scholar
- 28.Toyoda H. Item response theory—case example.In 項目反応理論[事例編]. 7th ed. Tokyo: Asakura Publishing Co., Ltd; 2014.Google Scholar