In recent years, workload has increased with higher precision of radiotherapy. Although both efficiency and thoroughness of treatment are crucial, in such conditions, human error is easy to occur. In this study, five incident cases that occurred in four facilities were studied and analyzed from the viewpoint of human factors that contribute to errors using variation tree analysis. We also analyzed resilience (the ability to return to one’s original state even if the system deviates from a stable state), which has attracted attention in recent safety research. There were potential factors represented by patient factors in all cases. These factors caused deviations from standard operations, and incidents occurred due to unfamiliar situations and operations. Furthermore, in four of the five cases, the cause of the incident was a resilience action or judgment that was deemed to have required “some sort of ingenuity or adjustment.” It was found that human error occurred due to multiple simultaneous occurrences of potential factors, i.e., patient and human factors such as high workload, impatience, and work interruptions. A reduction in human errors can be achieved by avoiding time pressure and multitasking, creating work environment and working conditions that make resilience work well, revising ambiguous rules and procedures, and promoting standardized working methods.
We analyzed 197 fall incidents in the questionnaire survey about the incident that occurred in Department of Radiology. In the past paper about the patient safety, there is no report that evaluated incident data directly. The purpose of this paper is to analyze the factor of the medical incidents using statistical technique scientifically. In this paper, we do not suggest concrete precaution. At first, we found the number of patients (each gender, modality, generation) in the five facilities of the coworker of one week. We found an incident rate from this patient total number, and we normalized data. As a result, we were able to do each risk evaluation because a risk ratio and relative risk degree was found. And, we were able to identify modality and the generation with the significant difference using the testing for differences in population rate. By our analyses, we revealed the chapter which must strengthen safety management.
For events with a low occurrence rate, such as medical incidents, we were able to determine the evaluation before and after taking medical safety measures by statistical methods (testing for differences in population rate). The point of this method is that we evaluated the occurrence rate of incidents to the total number of examinations (number of incident occurrence real number plus number of examinations carried out without any problems). Our results suggest that this technique becomes the evaluation technique as the effective method of medical safety measures. The present studies demonstrated that the evaluation technique by the testing for differences in population rate become the indicator to judge the effectiveness of the medical safety measures in the following cases. (1) When we evaluate the decrease in incident for the long term before and after safety measures. (2) When we evaluate the effectiveness of measures in the middle evaluation after safety measures.
Appropriate information security measures are very important for today’s highly computerized hospitals to maintain the trust from patients. If once the personal information leakage of medical information was occurred, the hospital could lose their trust that has built for long time so far. It is important for hospitals to know the impact of the leakage accident previously advance to decide the investment for information security. The purpose of this study is to evaluate the impact of medical information leakage. The comforting fee for the patient’s mental damage as the willingness to accept (WTA) was estimated, when the information leak occurred from a hospital using the contingent valuation method (CVM). Questionnaire survey was conducted using an internet survey service in Japan. We asked for 300 citizens about the use of personal information communication equipment and information security measures and their awareness for the information leakage. In addition, we presented a hypothetical scenario regarding information leakage of own medical information, asked the WTA as the comforting fee by the one choice of acceptance or rejection for the presented fee. In 300 responses, 190 were could be used for WTA estimation. WTA as the comforting fee when the information leakage of medical care information occurred, was estimated 570,541 yen in total. The result was similar with the value estimated by the damage compensation payment estimation model.
The work of radiological technologists is changing and more complicated because of the development of medical technology and implementation of information technology (IT). Although the cases of incident and accident have been reported, they have not been comprehensively analyzed in the workflow for radiotherapy. In this study, we visualized the workflow of radiological technologists in radiotherapy and revealed the causes of incidents and accidents. The work process was visualized by drawing workflow map. The structuring of problem was performed with interpretive structural modeling (ISM) method based on graph theory by analyzing of work categorized by safety management. Our results may be able to clarify the work of radiological technologists leads to the reduction of incidents and accidents in radiation therapy.
Purpose: When working on fluoroscopy and patient assistance in a healthcare facility, workers need to understand how to properly protect scattered radiation. In this study, we examined a four-dimensional visualization method to make it easy to understand the spread of scattered radiation visually, and proposed its application to radiation protection education. Methods: We constructed the X-ray room, X-ray CT room, and angiography room using Particle Heavy Ion Transport code System (PHITS), and calculated the scattered radiation distribution when the patient was irradiated with X-rays. The three-dimensional distribution of each moment was continuously displayed to create a four-dimensional distribution. Using the created data, we conducted radiation protection education including exercises to make the students confirm the scatter distribution from any direction. The effectiveness of the scattered radiation visualization data was evaluated by a questionnaire. Results: The position of assistance for standing chest radiograph was less scattered radiation at the side and below the patient. As a result of the questionnaire, this education has confirmed the effect of attracting attention about radiation protection. The fourdimensional visualization allowed students to understand the behavior of radiation and the source of scattered radiation. Conclusion: Visualization of three- and four-dimensional scattered radiation distribution in the radiological examination room can intuitively enhance the understanding of the invisible radiation spread and appropriate aids.
Purpose: The purpose of this study is to analyze the factors of patient’s fall that causes serious injury in the radiological examinations. Methods: We conducted a questionnaire survey on cases of medical accidents occurring in the radiological examination department in medical institutions. The number of responses to the questionnaire surveys was 372. Among them, 197 cases were related to fall. The incident influence classification divided into eight clusters (0, 0H, 1, 2, 3a, 3b, 4, 5) was divided into three clusters (tiny, moderate, serious injury) depending on severity. We analyzed the factors that cause serious injury. Results: In the case of patient’s fall, several factors have been found to cause serious injury. The factors were general radiography, standing position, outside working hours. Conclusion: All falls can cause serious injury. To reduce falls, it is important to analyze what kind of patient and in what situation tend to fall, and prevent falls in advance.
A common cause for image retakes in mammography is lack of proper positioning. Image retake is a potential hazard of increased radiation exposure to patient, patient discomfort and pain. Therefore, a mammographer has to provide fast exams with fewer retakes. Although evaluation of how a mammographer is effectively positioning has been studied in many ways, little research has been conducted to analyze visual attention. In this study, eye tracking system was adopted to detect eye movements and locations within a participants’ visual fields during positioning. Eye tracking system has been widely used for assessing technical skills and risk awareness, and for comparing the skills between experts and novices. Two skilled mammographers and two novices were recruited. Positioning related activities were divided into two phases: patient’s observation and breast positioning. Breast positioning was sub-divided into three stages to compare visual attention between experts and novices using heatmap and gaze plot. Although the expert tended to check each point, the novices tended to have a relatively short gaze of the outer breast region was observed. In the future, a comparative evaluation using clinical images is necessary; however, the eye tracking system to visualize attention contributes to medical safety during positioning.
The Japanese Ministry of Health, Labor and Welfare announced a revision of the law about the expansion of duties by the radiological technologist in team medical care in April, 2010. In that respect, the importance of reading images with support from the radiological technologist became higher. We compared the interpretation results of the radiologist with the image analysis by the radiological technologist of the CT images of emergency patients. And we checked for symptoms and diseases which were frequently overlooked by the technologists. Inexperienced radiological technologists overlooked considerably more than experienced radiological technologists. Our results showed that abdominal or chest image analysis differed more often than head scan analysis. The reasons given for the differences include a lack of clear indication for abdominal tumors, and we overlooked a lot of diseases such as pneumonia and enteritis. We also had several cases of abdominal and chest images over-reading by radiological technologists. To improve these, radiological technologists should deepen their knowledge of normal anatomy and work to improve recalling diseases that are inferred from the patient’s symptoms. This will greatly improve the image interpretation support by the radiological technologists.
We investigated the causes and trends of incidents related to radiography. From April 2014 to March 2016, 384 incident reports related to radiography were posted. We analyzed based on the nature of the incidents and the experience period of radiological technologist (RT). The types of incidents were ‘Incorrect examination order by medical doctor’ (50.0%), ‘X-ray retake’ (24%), ‘Incorrect examination procedure’ (9.9%), ‘Fall or injury of the patient under examination’ (3.6%), ‘selection error of X-ray detector’ (3.1%), ‘patient mismatch’ (1.8%), ‘overdose’ (1.3%), and ‘others’ (a malfunctioning device, trouble of systems and the other) (6.5%). There was no relationship between the number of incidents per person and the experience period as RT; (7.8/person for <3 years of experience, 9.7/person for 3–10 years, 6.4/person for 11–25 years of experience, 7.4/person for <25 years of experience). The experience period as RT are related to some types of incident reduction. ‘Fall or injury of the patient under examination’ and ‘overdose’ were more frequently reported by RTs of shorter experience (<3 years and 3–10 years of experience) than RTs of longer experience (11–25 years and <25 of experience). On the other hand, ‘patient mismatch’ and ‘selection error of X-ray detector’ were more frequently reported by RTs of long experience than RTs of short experience.
We conducted a questionnaire survey (situation, patient factor, environmental factor, operator factor, degree of disability, countermeasure etc.) on cases that occurred up to the present to investigate the actual situation of the medical accidents that occur in the radiological examination department of medical institutions. There were 373 questionnaires collected. Among them, there were 197 cases of falls. In this study, we examined the age of patients who fell, the background of the accident, and factors. As for the accident, 11.7% of accidents with risk impact level 3b or higher occurred including the fatal accident. Of the accidents, 44.2% were foreseeable and 55.8% were unforeseeable. The most accident-prone age was elderly in their 60s to 80s. As the causative factor for the accident, the patient factor was the largest at 63.5%. We can prevent about 30% of the accident by improving the operator factor and the environmental factor which are parts other than patient factor. It is important for us to understand what kind of people tend to fall. Among foreseeable accidents, the causes of patient factors can be reduced.
The safety management information related to heat generation in magnetic resonance imaging (MRI) examinations includes the specific absorption rate (SAR), the root mean square (RMS) of the MRI effective component of the B1 field (B1+rms), and imaging time, which must be set appropriately before an MRI examination. However, unlike image attributes and data, these three parameters do not require any image storage; therefore, information collection and confirmation post-inspection are difficult. Therefore, in this study, we used Digital Imaging and Communications in Medicine of SAR and imaging time using the overlay function of the picture archiving and communication systems (PACS) to confirm the specific absorption rate B1+rms and imaging time post-inspection. The medicine identification tag information was displayed on the PACS viewer. For some imaging times, the console display during scanning and the PACS viewer display did not match. However, the SAR console display during scanning and the PACS viewer display matched well, thereby rendering it easier to manage safety in MRI examinations.
Purpose: The purpose of this paper is to analyze the characteristics of incidents related to routes and drains that occur in the radiological examination room for the prevention of these incidents. Methods: We conducted a questionnaire survey on incident cases that occurred in the radiological examination room. There were 373 responses, of which 76 responses were related to routes and drains. The question contents were the number of hospital beds, radiology department of occurrence, time of occurrence, patient’s situation, method of visiting, years of experience of the radiological technologists, and countermeasures, and so on. Based on these answers to these questions, we analyzed which factors were involved in the occurrence of the incidents. Results: Incidents related to routes and drains often occur when moving examination table or transferring the patients to the examination table using the slider. On the other hand, the years of experience of the radiological technologists hardly participated in the factor of these incidents. From these answers to questions, 75% of incidents might predictable, and these incidents could be prevented by improvement of human factors accounted for the majority rather than that of physical factors. Conclusion: The number of incidents related to routes and drains may reduce by that all staff involved in the radiological examination recognizing the characteristic of these incidents.