Workplace bullying (WB) assessment often relies on the Negative Acts Questionnaire-Revised (NAQ-R). This study aimed to shorten and improve the NAQ-R using Item Response Theory (IRT) and address sex bias. IRT analysis from 867 Swedish employees (66% women) identified less-informative items. Based on this, a 13-item NAQ-R Short Form (NAQ-R-SF) was developed, demonstrating strong discrimination and validity. The new NAQ-R-SF showed a significant correlation with a primary WB measure (r = .57) and other relevant constructs, including individual factors like neuroticism and health quality, as well as work-related factors such as interpersonal conflicts and work performance. Sex bias was not found. IRT and validity evidence support the NAQ-R-SF as a robust tool for measuring WB, aligning with established WB constructs and individual differences.

The authors have declared no competing interest.

The author(s) received no specific funding for this work.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The study was conducted in accordance with the Swedish Ethical Review Act (SFS 2003:460). Prior to commencing data sampling in 2015, this study underwent consultation with a scientific secretary at the former Regional Ethical Board, now known as the Swedish Ethical Review Authority. Formal approval by the Ethical Review Authority was not required for this study, as it focuses solely on psychometric analysis of an anonymous questionnaire, without involving experiments or sensitive data usage. All protocols for methods and analyses were in line with Lund University’s internal ethical guidelines. Data collection did not involve manipulation or deception tactics, and was conducted voluntarily. It involved anonymous standardized questionnaires, ensuring participant confidentiality and adherence to ethical standards. Written consent was obtained following the Declaration of Helsinki.

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The data underlying the results presented in the study are available from Mendeley (doi: 10.17632/mgwtzjww7g.1)