Becoming a physician requires a high level of medical knowledge and skill in order to deal with issues of life and death, and residents must pass intense training courses to acquire the required skills. A resident receives training in an educational hospital or medical institute in order to acquire a license as a medical specialist. According to data collected by the Korean Medical Association, there were 14,633 residents as of December 31, 2008, accounting for 18.6% of the 78,518 total physicians working in the medical field. Most residents work in educational hospitals, where they often play important roles as primary physicians. Like students of medical schools or graduate schools of medicine, they are also in training to become qualified medical specialists. However, residents work in educational hospitals and have a lower economic status and social position relative to the larger community of physicians. Residents often commit a variety of medical errors because of heavy job stress and fatigue. In addition, hospitals often fail to provide management to reduce job stress, and residents often feel that they cannot state their needs due to their position as trainees. Hospitals often consider them as low-cost operating labor and consider the improvement of systems or facilities associated with medical training as a hindrance to hospital operations, and therefore little effort is made to improve conditions for residents and their training program.

Medical errors and the safety of patients are important issues for both patients and physicians. In the US in 1999, it was reported that about 100,000 patients died from previously preventable side effects and this has significant implications for both physicians and patients.¹⁾ Studies regarding medical errors report that resident fatigue and sleepiness are major factors in medical errors.^1-4) Another study reports that resident burnout from stress is a major cause of self-reported medical errors.⁵⁾ Continued and repeated stress results in burnout⁶⁾ by inducing physical, emotional, and mental exhaustion. It is easy to understand why fatigue may cause medical errors. However, because fatigue or sleepiness may affect burnout, there is a need for studies solely on burnout apart from fatigue and sleepiness. This study intends to help improve both patient safety and resident training conditions by understanding the relationship between resident burnout and subsequent medical errors.

Although stress experienced by residents in hospitals is unavoidable, the degree of stress may be greater than that experienced by those in other professions.²³⁾ Some amount of stress may be helpful for the management of patients, but when sustained unbearable stress is experienced, this may affect physical and mental health and result in burnout.^24,25) Burnout, a symptom caused by continued stress, is a result of emotional pressure developed by long-term repeated exposure to continuous occupational stress.²⁶⁾ According to Maslach et al.,¹²⁾ burnout can be divided into emotional exhaustion, depersonalization, and personal accomplishment, and can be measured by the MBI scale.

In this study, we found that subjects who experienced high degrees of emotional exhaustion and depersonalization reported more medical errors. This result was partially consistent with a study conducted by West et al.²¹⁾ that found higher degrees of emotional exhaustion and depersonalization and lower feelings of personal accomplishment were associated with a higher frequency of medical errors.²⁷⁾ In a study of internal medicine physicians at the Mayo, West et al.²¹⁾ found that burnout was related to self-reported medical errors, independent of fatigue. In particular, when controlling for daytime sleepiness, severe emotional exhaustion and depersonalization were associated with higher rates of medical errors. When controlling for fatigue, severe emotional exhaustion and depersonalization and a lower sense of personal accomplishment were also associated with medical errors. In this study, the results of univariate analysis suggest that emotional exhaustion and depersonalization are associated with medical errors. In the multivariate logistic regression analysis controlling for daytime sleepiness, only emotional exhaustion was significantly related with medical errors and depersonalization was associated with daytime sleepiness. Depersonalization is defined as a state in which patients are regarded as cases rather than as people and physicians may come to develop a negative or sarcastic attitude toward patients or their care-givers and become uncooperative.¹²⁾ Because residents go without sleep for long periods during their training, they often feel sleepy in the daytime in spite of sufficient sleep at night. As a result, it is thought that residents often lose motivation for their work and come to have passive attitudes toward their patients. When controlling for fatigue, a higher degree of depersonalization was associated with significantly more medical errors. It is thought that if someone is tired and his/her energy is depleted, mental and physical resources are also reduced, finally leading to emotional exhaustion. Comparing this study with the study by West et al.²¹⁾ there were some statistically significant differences with respect to the sub-areas of burnout, but these differences were due to the longer duration of their study period (from 2003 to 2008, with three month intervals) and larger number of subjects (430 residents of internal medicine). Maslach et al.¹²⁾ defined burnout as over 27 points for emotional exhaustion or over 10 points for depersonalization, and emphasized that the three areas of burnout should be considered separately because they represent different aspects of this condition.¹³⁾ Therefore, this study suggests that burnout is associated with self-reported medical errors regardless of fatigue and daytime sleepiness.

The study by West et al.²¹⁾ indicated that burnout, as well as fatigue, must be addressed in the discussion of the improvement of medical training courses in the US.²⁷⁾ Similarly, it may be beneficial when planning medical training courses in Korea, to recognize a need to develope a strategy to alleviate burnout because burnout negatively affects the quality of medical service. Furthermore, like the study by Gopal et al.¹⁷⁾ reporting that when resident working hours were reduced, the degree of burnout decreased, more studies that affect burnout are needed.

There are several limitations to this study. First, although the purpose of this study was to assess the relationship between burnout and medical errors, it was difficult to identify a causal relationship because medical errors were reported for the previous three months and burnout was assessed at the time of the survey. Because of this issue, results are best interpreted as associations rather than as definitive evidence of causation. Second, because medical errors were evaluated via self-report, it did not directly reflect clinically documented medical errors and could be arbitrary. Third, severity of medical errors was not considered. It was impossible to judge precisely if self-reported medical errors resulted in actual harm to patients. However, it is necessary to recognize that self-reported medical errors may be more likely to represent preventable medical errors. The fourth is the fact that the response rate was only 58.5%, and an analysis of characteristics of the non-respondents was not carried out. Fifth, because this study was performed at a university hospital in Busan, results may not be applicable to all medical residents. In the future, larger sample sizes may be necessary to better generalize this association. However, considering the fact that Korean studies of medical errors of residents are lacking, this study is an important step in identifying the relationship between resident burnout and self-reported medical errors in spite of its limitations.