ORIGINAL RESEARCH PAPER The effect of workload on nurses' non‐observance errors in medication administration processes: A cross‐sectional study Haizhe Jin PhD, Lecturer 1 | Han Chen MS, Master Student 1 | Masahiko Munechika PhD, Professor 2 | Masataka Sano PhD, Associate Professor 3 | Chisato Kajihara PhD, Assistant Professor 4 1 Department of Industrial Engineering, Northeastern University, Shenyang, China 2 Faculty of Science and Engineering, Waseda University, Tokyo, Japan 3 Department of Management Information Science, Chiba Institute of Technology, Chiba, Japan 4 Department of Industrial and Management Systems Engineering, Waseda University, Tokyo, Japan Correspondence Haizhe Jin, Department of Industrial Engineering, Northeastern University, 3‐11, Wenhua Road, Heping District, Shenyang, China. Email: hzjin@mail.neu.edu.cn Funding information National Natural Science Foundation of China, Grant/Award Number: 71471003; Fundamental Research Funds for the Central Universities, Grant/Award Number: N170604005 Abstract Aim: This study, based on actual medical error cases involving nurses, sought to identify non‐observance errors—defying the standard operating procedures—in medication adminis- tration processes, and clarify the relationship between nursing workload and such behaviours. Methods: Based on a cross‐sectional survey, non‐observance error cases were collected from three Japanese hospitals between January and December 2014, using self‐reported data from participating nurses. Standard operating procedures and actual error content were compared to identify non‐observance errors and workload. The statistical analysis was used to determine the relationship between non‐observance error and workload. Results: A total of 637 error cases were found in administering medication, of which 163 (25.6%) were workload‐related non‐observance errors. Individual analysis of the 163 cases identified seven workload issues that caused non‐observance error and six categories of non‐observance errors. The relationship between workload and such errors was also clarified. Conclusion: Our findings clarify the influence of workload on non‐observance errors and may also help identify adjacent areas for specific improvements. KEYWORDS administering medicine process, health care, non‐observance error, nursing workload, partial least squares (PLS) SUMMARY STATEMENT What is already known about the topic? • Previous studies of nursing workload have focused on the physical and psychological effects of workload, with few studies discussing the relationship between workload and non‐observance errors. What this paper adds? • Our findings on the relationship between workload and non‐obser- vance errors support the human factors theory in workload‐related medical non‐observance errors and provide effective direction for improving these errors. • We identified seven workload factors that may cause non‐obser- vance error in the process of administering medicine, and six kinds of non‐observance errors The implications of this paper: • The findings offer a specific idea for the safety managers of hospi- tals regarding how to prevent non‐observance. • The workloads, non‐observance errors, and corresponding relationship between them can be used as educational materials, so that nurses can deeply understand the causes and hazards of non‐observance and prevent similar errors from happening again. Received: 31 May 2017 Revised: 4 April 2018 Accepted: 18 June 2018 DOI: 10.1111/ijn.12679 Int J Nurs Pract. 2018;e12679. https://doi.org/10.1111/ijn.12679 © 2018 John Wiley & Sons Australia, Ltd wileyonlinelibrary.com/journal/ijn 1 of 9