Toward An Action Based Taxonomy of Human Errors in Medicine

Toward An Action Based Taxonomy of Human Errors in Medicine Jiajie Zhang 1 , Vimla L. Patel 2 , Todd R. Johnson 1 , & Edward H. Shortliffe 2 School of Health Information Sciences University of Texas at Houston 7000 Fannin, Houston, TX 77030 {Jiajie.Zhang, Todd.R.Johnson}@uth.tmc.edu Abstract One critical step in addressing and resolving the problems as- sociated with human errors is the development of a cognitive taxonomy of such errors. In the case of errors, such a taxon- omy may be developed (1) to categorize all types of errors along cognitive dimensions, (2) to associate each type of error with a specific underlying cognitive mechanism, (3) to ex- plain why, and even predict when and where, a specific error will occur, and (4) to generate intervention strategies for each type of error. Based on Reason’s (1992) definition of human errors and Norman’s (1986) cognitive theory of human action, we have developed a preliminary action-based cognitive taxonomy of errors that largely satisfies these four criteria in the domain of medicine. We discuss initial steps for applying this taxonomy to develop an online medical error reporting system that not only categorizes errors but also identifies problems and generates solutions. 1. Introduction The medical error report from the Institute of Medicine (Kohn, Corrigan, & Donaldson, 1999) has greatly in- creased people’s awareness of the frequency, magnitude, complexity, and seriousness of medical errors. As the 8th leading cause of death in the US with 98,000 preventable deaths per year, ahead of motor vehicle accidents, breast cancer, or AIDS, medical errors need immediate attention from academic, healthcare, and government institutions and organizations. To achieve the goal of reducing medical errors by 50% in five years set by the former Clinton Ad- ministration, we need to understand the fundamental causes of medical errors such that medical errors can be prevented or greatly reduced systematically at a large scale. In our opinion, cognitive factors are fundamental in medi- cal errors. This can be seen from the view of the healthcare system hierarchy and the view of action chains. Cognitive factors are critical at various levels of the healthcare system hierarchy of medical errors (Figure 1). At the lowest core level, it is individuals who trigger er- rors. Cognitive factors of individuals play the most critical role here (Reason, 1992). At the next level, errors can oc- cur due to interactions between an individual and technol- ogy. This is an issue of human-computer interaction where cognitive properties of interactions between human and technology affect and sometimes determine human behav- ior (Helander, Landauer, & Prabhu, 1997; Zhang, 1997; Department of Medical Informatics Columbia University 622 West 168th Street, New York, NY 10032 {Patel, Shortliffe}@dmi.columbia.edu Zhang & Norman, 1994). At the next level, errors can be attributed to the social dynamics of interactions between groups of people who interact with complex technology in a distributed cognitive system. This is the issue of distributed cognition and computer-supported cooperative work (Baecker, 1993; Hutchins, 1995a, 1995b; Zhang, 1997). At the next few levels up, errors can be attributed to factors of organizational structures (e.g., coordination, communica- tions, standardization of work process), institutional func- tions (e.g., policies and guidelines), and national regula- tions. At these higher levels, cognitive factors also play some roles. Although the properties at the six levels can be to some extent studied independently, a cognitive founda- tion for the system is essential for a complete and in-depth understanding of medical errors. National Regulations Institutional functions (policy, guidelines) Organizat ional structures (coordination, commun ication, and standardizat ion of work process, skills, input and output) Distributed systems: interactions among indiv iduals and interact ions between groups of people and techonology Individual-techonology interaction Individuals Figure 1. The system hierarchy of human errors in medicine From the view of action chains, the critical roles of cognitive factors in medical errors are also clear. Figure 2 shows the chain of events and factors that lead to an error in a system. It is clear that individuals are at the last stage of the chain, although the individuals may not be the root cause of the error. If the chain of events can be stopped at the in-