Database construction for improving patient safety by examining pathology errors

A critical component of improving patient safety is reducing medical errors. "Improving Patient Safety by Examining Pathology Errors" is a project designed to collect data about and analyze diagnostic errors voluntarily reported by 4 academic anatomic pathology laboratories and to develop and implement interventions to reduce errors and improve patient outcomes. The study database is Web-mediated and Oracle-based, and it houses de-identified error data detected by cytologic-histologic correlation and interdepartmental conference review. We describe the basic design of the database with a focus on challenges faced as a consequence of the absence of standardized and detailed laboratory workload and quality assurance data sets in widely used laboratory information systems and the lack of efficient and comprehensive electronic de-identification of unlinked institutional laboratory information systems and clinical data. Development of these electronic data abstraction capabilities is critical for efforts to improve patient safety through the examination of pathology diagnostic errors.     

A cognitive taxonomy of medical errors

OBJECTIVE: Propose a cognitive taxonomy of medical errors at the level of individuals and their interactions with technology. DESIGN: Use cognitive theories of human error and human action to develop the theoretical foundations of the taxonomy, develop the structure of the taxonomy, populate the taxonomy with examples of medical error cases, identify cognitive mechanisms for each category of medical error under the taxonomy, and apply the taxonomy to practical problems. MEASUREMENTS: Four criteria were used to evaluate the cognitive taxonomy. The taxonomy should be able (1) to categorize major types of errors at the individual level along cognitive dimensions, (2) to associate each type of error with a specific underlying cognitive mechanism, (3) to describe how and explain why a specific error occurs, and (4) to generate intervention strategies for each type of error. RESULTS: The proposed cognitive taxonomy largely satisfies the four criteria at a theoretical and conceptual level. CONCLUSION: Theoretically, the proposed cognitive taxonomy provides a method to systematically categorize medical errors at the individual level along cognitive dimensions, leads to a better understanding of the underlying cognitive mechanisms of medical errors, and provides a framework that can guide future studies on medical errors. Practically, it provides guidelines for the development of cognitive interventions to decrease medical errors and foundation for the development of medical error reporting system that not only categorizes errors but also identifies problems and helps to generate solutions. To validate this model empirically, we will next be performing systematic experimental studies.     

The SHEL model: a useful tool for analyzing and teaching the contribution of Human Factors to medical error.

Recent reports on the problem of medical error pointed to a discipline that has been until recently, largely disregarded by the medical profession. The interdisciplinary science of Human Factors, the reports argue, provides a pragmatic framework for analyzing and assessing risk and reducing error in health care. The argument for applying Human Factors analysis to health care is increasingly accepted, and the application of Human Factors systems models for understanding medical error in particular have proved to be especially illuminating. The authors present a conceptual model of Human Factors--the SHEL model (named after the initial letters of its components' names, Software, Hardware, Environment, and Liveware)--that has been used in investigations of error in aviation. The authors use this simple model to examine and elucidate the Human Factors issues in a specific real-life example of medical error. The SHEL model is particularly useful in examining Human Factors issues in microsystems in health care such as the emergency room or the operating theatre; it argues that mismatches at the interface between the components in these health care microsystems are often conducive to medical errors. The authors propose that the SHEL model may have some unexploited potential in analyzing error and in training medical professionals about the science of Human Factors and its application to medical error. Empirical studies are needed, however, to ascertain the optimal amount of training needed to make clinically significant reductions in the occurrence of medical error.     

Influence of dose engine accuracy on the optimum dose distribution in intensity-modulated proton therapy treatment plans

Analytical dose computation algorithms like pencil beam algorithms (PB) are presently used for clinical treatment planning in intensity-modulated proton therapy. PB offer fast computation times, but are based on substantial approximations. Monte Carlo algorithms (MC) offer better accuracy, but are slower. We present a comparison of optimized treatment plans for six patients computed either with PB or MC. Both PB and MC are used during optimization, plus MC is used to recompute PB results. PB is used with different accuracy settings that define the coarseness of approximation. We evaluate the errors of PB optimized treatment plans via comparison with MC optimized plans (convergence errors) and MC recomputed plans (systematic errors) occurring for different accuracy settings of the PB. The level of lateral heterogeneities, being one of the main sources of inaccuracies of the PB, is quantified by a formula. In geometries with high levels of lateral heterogeneities, the shortcomings of PB are most obvious. For these geometries, simple PB lead to clinically significant differences and more accurate PB settings have to be used to diminish the error. The most accurate PB settings lead however to longer computing times by approximately a factor of 2 to 4 compared to PB with simple settings. Although the errors can be diminished, they cannot be fully eliminated even with sophisticated PB. Further gain in accuracy can therefore only be reached with MC in optimization. The use of MC in optimization is technically feasible, the computing times are however about 25 to 50 times longer compared to PB with most accurate settings.     

The effect of withdrawal of visual presentation of errors upon the frequency spectrum of tremor in a manual task

1. When a subject attempts to exert a steady pressure on a joystick he makes small unavoidable errors which, irrespective of their origin or frequency, may be called tremor.2. Frequency analysis shows that low frequencies always contribute much more to the total error than high frequencies. If the subject is not allowed to check his performance visually, but has to rely on sensations of pressure in the finger tips, etc., the error power spectrum plotted on logarithmic co-ordinates approximates to a straight line falling at 6 db/octave from 0.4 to 9 c/s. In other words the amplitude of the tremor component at each frequency is inversely proportional to frequency.3. When the subject is given a visual indication of his errors on an oscilloscope the shape of the tremor spectrum alters. The most striking change is the appearance of a tremor peak at about 9 c/s, but there is also a significant increase of error in the range 1-4 c/s. The extent of these changes varies from subject to subject.4. If the 9 c/s peak represents oscillation of a muscle length-servo it would appear that greater use is made of this servo when positional information is available from the eyes than when proprioceptive impulses from the limbs have to be relied on.     

Questions on validity of International Classification of Diseases-coded diagnoses

International Classification of Diseases (ICD) codes are used for indexing medical diagnoses for various purposes and in various contexts. According to the literature and our personal experience, the validity of the coded information is unsatisfactory in general, however the 'correctness' is purpose and environment dependent. For detecting potential error sources, this paper gives a general framework of the coding process. The key elements of this framework are: (1) the formulation of the established diagnoses in medical language; (2) the induction from diagnoses to diseases; (3) indexing the diseases to ICD categories; (4) labelling of the coded entries (e.g. principal disease, complications, etc.). Each step is a potential source of errors. The most typical types of error are: (1) overlooking of diagnoses; (2) incorrect or skipped induction; (3) indexing errors; (4) violation of ICD rules and external regulations. The main reasons of the errors are the physician's errors in the primary documentation, the insufficient knowledge of the encoders (different steps of the coding process require different kind of knowledge), the internal inconsistency of the ICD, and some psychological factors. Computer systems can facilitate the coding process, but attention has to be paid to the entire coding process, not only to the indexing phase.     

Communicating pathology and laboratory errors: anatomic pathologists' and laboratory medical directors' attitudes and experiences

Physicians are urged to communicate more openly following medical errors, but little is known about pathologists' attitudes about reporting errors to their institution and disclosing them to patients. We undertook a survey to characterize pathologists' and laboratory medical directors' attitudes and experience regarding the communication of errors with hospitals, treating physicians, and affected patients. We invited 260 practicing pathologists and 81 academic hospital laboratory medical directors to participate in a self-administered survey. This survey included questions regarding estimated error rates and barriers to and experience with error disclosure. The majority of respondents (~95%) reported having been involved with an error, and respondents expressed near unanimous belief that errors should be disclosed to hospitals, colleagues, and patients; however, only about 48% thought that current error reporting systems were adequate. In addition, pathologists expressed discomfort with their communication skills in regard to error disclosure. Improving error reporting systems and developing robust disclosure training could help prevent future errors, improving patient safety and trust.     

Medical errors – not only patients’ problem

Introduction

Medical error is often a traumatic experience not only for patients but also for doctors. However, patients as victims get much more publicity than those responsible for actual errors. The authors of the study conducted research to learn about Polish doctors'' opinions on and reactions to medical errors and how they affect their further professional activity and psychological status. The aim of this study was to evaluate the impact of involvement in medical errors of doctors of different specialties and different age.

Material and methods

The research was conducted in a group of 100 doctors of different specialties. Respondents anonymously completed an experimental survey comprising 6 groups of multiple choice questions concerning such issues as awareness of the nature of medical error, legal liability of the perpetrator, consequences of medical error for further professional activity, the function of the Patients'' Rights Representative and consequences of publishing the problem.

Results

The results indicate many negative effects of medical errors on physicians, such as common fear of making an error (82%), increased caution (52%), disadvantageous security measures while performing one''s duties (57%), worsening of doctor-patient relations (67%), loss of social trust (62%) and increased treatment costs (40%). Forty five percent of the surveyed doctors declared that patients need the Patients'' Rights Representative and 39% claimed it does not affect their work.

Conclusions

Given the significant burden on physicians'' health, well-being and performance associated with medical errors, health care institutions should take this into account and provide physicians with formal systems of support.     

Quality assurance of analytical methods to guarantee the reliability of medical decision levels for interpretation of clinical laboratory data

We sought to investigate the effects of measurement errors on the evaluation of biological variations in healthy subjects. To this end, we analyzed the allowable limits of analytical error which can guarantee the reliability of medical decision levels for interpretation of clinical laboratory data. As a conclusion, we suggest that one-half or less of biological intra-individual variations is appropriate as the criterion for an allowable limit of error to be applied in health check-ups, and this value is in agreement with those in previous reports. If this criteria as the marker for intra-laboratory imprecision is met, a given institute should be able to evaluate time series change follow up of individual data. If the reference interval of laboratory data for disease screening is shared by different institutes, the criterion of 1/4 or less of a biological inter pulse intra-individual variation should be appropriate. This criterion appears to be the goal to be achieved for analytical inter-laboratory variations. On the other hand, as for the criterion for measurement errors which guarantees disease identification based on the cut-off value, a criterion of 1/4 or less of biological inter-pulse intra-individual variation appears to be appropriate, taking into consideration measurement errors which did not influence false-positive or false-negative rates of disease identification. The value turned out to be the same as the limit for the screening of disease. In this study, we considered allowable limits of error in the vicinity of reference value concentrations. However, it will be necessary to set separately the criteria for data in abnormal ranges.     

Quality of medication use in primary care - mapping the problem, working to a solution: a systematic review of the literature

Background  

The UK, USA and the World Health Organization have identified improved patient safety in healthcare as a priority. Medication error has been identified as one of the most frequent forms of medical error and is associated with significant medical harm. Errors are the result of the systems that produce them. In industrial settings, a range of systematic techniques have been designed to reduce error and waste. The first stage of these processes is to map out the whole system and its reliability at each stage. However, to date, studies of medication error and solutions have concentrated on individual parts of the whole system. In this paper we wished to conduct a systematic review of the literature, in order to map out the medication system with its associated errors and failures in quality, to assess the strength of the evidence and to use approaches from quality management to identify ways in which the system could be made safer.     

Examination for prevent of blood transfusion errors

Human error has identified as a major source of ABO incompatibility-related transfusion fatalities. Frequency of ABO-incompatible transfusion has been reported to range from 2.5 to 253 per 100,000 transfusion units. Transfusion error has developed various occasions, for example, wrong specimen and patients, specimen exchange and mistake of ABO compatibility test. In laboratory examination, many errors were occurred during night shift, because it was necessary to established the examination system. We discussed about examination for prevent of blood transfusion errors.     

网络环境下医学信息工作的创新与发展

在信息时代,医学信息工作必须创新,才能求得发展。本文探讨了医学信息工作的创新方法:创新文献采编方式、创造全方位信息服务环境、文献复制及文献传递服务、主页服务、深化参考咨询服务、强调个性化信息服务、探索智能化检索路径、全球服务。     

Online Error Reporting for Managing Quality Control Within Radiology

Information technology systems within health care, such as picture archiving and communication system (PACS) in radiology, can have a positive impact on production but can also risk compromising quality. The widespread use of PACS has removed the previous feedback loop between radiologists and technologists. Instead of direct communication of quality discrepancies found for an examination, the radiologist submitted a paper-based quality-control report. A web-based issue-reporting tool can help restore some of the feedback loop and also provide possibilities for more detailed analysis of submitted errors. The purpose of this study was to evaluate the hypothesis that data from use of an online error reporting software for quality control can focus our efforts within our department. For the 372,258 radiologic examinations conducted during the 6-month period study, 930 errors (390 exam protocol, 390 exam validation, and 150 exam technique) were submitted, corresponding to an error rate of 0.25 %. Within the category exam protocol, technologist documentation had the highest number of submitted errors in ultrasonography (77 errors [44 %]), while imaging protocol errors were the highest subtype error for computed tomography modality (35 errors [18 %]). Positioning and incorrect accession had the highest errors in the exam technique and exam validation error category, respectively, for nearly all of the modalities. An error rate less than 1 % could signify a system with a very high quality; however, a more likely explanation is that not all errors were detected or reported. Furthermore, staff reception of the error reporting system could also affect the reporting rate.     

Effects of modeling errors on least squares error solutions to the inverse problem of electrocardiology

Modeling errors produced by differences between an actual electrical source in the heart and a model of the source have effects on least squares error (LSE) solutions for the model. These effects are analyzed using linear algebra theory and some modeling errors representative of those for actual heart measurements. It is found that increasing the number of dipoles in a multiple-dipole (MD) model increases the sensitivity of the solutions to small modeling error changes while increasing the number of terms in a multipole expansion (ME) model is likely to improve the accuracy of the solution for the dipolar terms. The results show that a MD model with more than two free-orientation dipoles will not provide accurate, useful, or reliable information for the representative modeling errors. Accurate solutions for the dipolar terms in a ME model are obtained for a model containing dipole, quadrupole, and octupole terms for these modeling errors. A new type of “average” LSE (AVL) solution for MD models with fixed-orientation dipoles is developed and compared with LSE and nonnegative LSE (NNL) solutions; the AVL solutions are found to be least sensitive to small modeling error changes but to provide misleading information for certain modeling errors. Finally, it is found that once a certain density of measurements is reached, the effects of modeling errors are nearly independent of the measurements used and, hence, no improvement in the solutions can be obtained by increasing the number of measurements. Work supported by National Heart, Lung, and Blood Institute; Grant #5R23HL24645.     

Accuracy of Computational Hemodynamics in Complex Arterial Geometries Reconstructed from Magnetic Resonance Imaging

Purpose: Combining computational blood flow modeling with three-dimensional medical imaging provides a new approach for studying links between hemodynamic factors and arterial disease. Although this provides patient-specific hemodynamic information, it is subject to several potential errors. This study quantifies some of these errors and identifies optimal reconstruction methodologies. Methods: A carotid artery bifurcation phantom of known geometry was imaged using a commercial magnetic resonance (MR) imager. Three-dimensional models were reconstructed from the images using several reconstruction techniques, and steady and unsteady blood flow simulations were performed. The carotid bifurcation from a healthy, human volunteer was then imaged in vivo, and geometric models were reconstructed. Results: Reconstructed models of the phantom showed good agreement with the gold standard geometry, with a mean error of approximately 15% between the computed wall shear stress fields. Reconstructed models of the in vivo carotid bifurcation were unacceptably noisy, unless lumenal profile smoothing and approximating surface splines were used. Conclusions: All reconstruction methods gave acceptable results for the phantom model, but in vivo models appear to require smoothing. If proper attention is paid to smoothing and geometric fidelity issues, models reconstructed from MR images appear to be suitable for use in computational studies of in vivo hemodynamics. © 1999 Biomedical Engineering Society. PAC99: 8719Uv, 8761-c, 0705Pj, 8710+e     

Patients' knowledge and perceived reactions to medical errors in a tertiary health facility in Nigeria

Background

Human errors in healthcare delivery pose serious threats to patients undergoing treatment. While clinical concern is growing in response, there is need to report social and behavioural context of the problem in Nigeria.

Objective

To examine patients'' knowledge and perceived reactions to medical errors.

Methods

A cross-sectional survey was conducted using a semi-structured questionnaire was used to collect data from 269 in-patients and 10 In-Depth Interviews were conducted among health caregivers in the University of Calabar Teaching Hospital, Nigeria.

Results

Majority (64.5%) of respondents reported annoyance and disappointment with medical errors. Severity of error (88.5%) and the perception of negligence mediated intention to litigate. Voluntary disclosure significantly reduced patients'' intention to litigate caregivers (chi²=3.584; df=1; P=0.053). Frustration/anger was not more likely to influence patient to litigate than feelings of resignation/forgiveness (chi²=2.156; df=1; P>.05). Financial difficulties arising from error had an important influence on litigation. Health caregivers admitted possibility of errors; and insisted that although notifying patients/relatives about errors is appropriate, disclosure was dependent on the seriousness, health implications and the causes.

Conclusion

Voluntary disclosure and teamwork is very important in dealing with medical error. The role of medical social workers could be important in the discourse and disclosure of medical error.     

Assessing medical students' clinical sciences knowledge in France: a collaboration between the NBME and a consortium of French medical schools.

PURPOSE: The French government, as part of medical education reforms, has affirmed that an examination program for national residency selection will be implemented by 2004. The purpose of this study was to develop a French multiple-choice (MC) examination using the National Board of Medical Examiners' (NBME) expertise and materials. METHOD: The Evaluation Standardisée du Second Cycle (ESSC), a four-hour clinical sciences examination, was administered in January 2002 to 285 medical students at four university test sites in France. The ESSC had 200 translated and adapted MC items selected from the Comprehensive Clinical Sciences Examination (CCSE), an NBME subject test. RESULTS: Less than 10% of the ESSC items were rejected as inappropriate to French practice. Also, the distributions of ESSC item characteristics were similar to those reported with the CCSE. The ESSC also appeared to be very well targeted to examinees' proficiencies and yielded a reliability coefficient of.91. However, because of a higher word count, the ESSC did show evidence of speededness. Regarding overall performance, the mean proficiency estimate for French examinees was about 0.4 SD below that of a CCSE population. CONCLUSIONS: This study provides strong evidence for the usefulness of the model adopted in this first collaborative effort between the NBME and a consortium of French medical schools. Overall, the performance of French students was comparable to that of CCSE students, which was encouraging given the differences in motivation and the speeded nature of the French test. A second phase with the participation of larger numbers of French medical schools and students is being planned.