Laura Zwaan

Patient record review of the incidence, consequences, and causes of diagnostic adverse events

BACKGROUND Diagnostic errors often result in patient harm. Previous studies have shown that there is large variability in results in different medical specialties. The present study explored diagnostic adverse events (DAEs) across all medical specialties to determine their incidence and to gain insight into their causes and consequences by comparing them with other AE types. METHODS A structured review study of 7926 patient records was conducted. Randomly selected records were reviewed by trained physicians in 21 hospitals across the Netherlands. The method used in this study was based on the well-known protocol developed by the Harvard Medical Practice Study. All AEs with diagnostic error as the main category were selected for analysis and were compared with other AE types. RESULTS Diagnostic AEs occurred in 0.4% of hospital admissions and represented 6.4% of all AEs. Of the DAEs, 83.3% were judged to be preventable. Human failure was identified as the main cause (96.3%), although organizational- and patient-related factors also contributed (25.0% and 30.0%, respectively). The consequences of DAEs were more severe (higher mortality rate) than for other AEs (29.1% vs 7.4%). CONCLUSIONS Diagnostic AEs represent an important error type, and the consequences of DAEs are severe. The causes of DAEs were mostly human, with the main causes being knowledge-based mistakes and information transfer problems. Prevention strategies should focus on training physicians and on the organization of knowledge and information transfer.

To what extent are adverse events found in patient records reported by patients and healthcare professionals via complaints, claims and incident reports?

BackgroundPatient record review is believed to be the most useful method for estimating the rate of adverse events among hospitalised patients. However, the method has some practical and financial disadvantages. Some of these disadvantages might be overcome by using existing reporting systems in which patient safety issues are already reported, such as incidents reported by healthcare professionals and complaints and medico-legal claims filled by patients or their relatives. The aim of the study is to examine to what extent the hospital reporting systems cover the adverse events identified by patient record review.MethodsWe conducted a retrospective study using a database from a record review study of 5375 patient records in 14 hospitals in the Netherlands. Trained nurses and physicians using a method based on the protocol of The Harvard Medical Practice Study previously reviewed the records. Four reporting systems were linked with the database of reviewed records: 1) informal and 2) formal complaints by patients/relatives, 3) medico-legal claims by patients/relatives and 4) incident reports by healthcare professionals. For each adverse event identified in patient records the equivalent was sought in these reporting systems by comparing dates and descriptions of the events. The study focussed on the number of adverse event matches, overlap of adverse events detected by different sources, preventability and severity of consequences of reported and non-reported events and sensitivity and specificity of reports.ResultsIn the sample of 5375 patient records, 498 adverse events were identified. Only 18 of the 498 (3.6%) adverse events identified by record review were found in one or more of the four reporting systems. There was some overlap: one adverse event had an equivalent in both a complaint and incident report and in three cases a patient/relative used two or three systems to complain about an adverse event. Healthcare professionals reported relatively more preventable adverse events than patients.Reports are not sensitive for adverse events nor do reports have a positive predictive value.ConclusionsIn order to detect the same adverse events as identified by patient record review, one cannot rely on the existing reporting systems within hospitals.

Exploring the causes of adverse events in hospitals and potential prevention strategies

Objectives To examine the causes of adverse events (AEs) and potential prevention strategies to minimise the occurrence of AEs in hospitalised patients. Methods For the 744 AEs identified in the patient record review study in 21 Dutch hospitals, trained reviewers were asked to select all causal factors that contributed to the AE. The results were analysed together with data on preventability and consequences of AEs. In addition, the reviewers selected one or more prevention strategies for each preventable AE. The recommended prevention strategies were analysed together with four general causal categories: technical, human, organisational and patient-related factors. Results Human causes were predominantly involved in the causation of AEs (in 61% of the AEs), 61% of those being preventable and 13% leading to permanent disability. In 39% of the AEs, patient-related factors were involved, in 14% organisational factors and in 4% technical factors. Organisational causes contributed relatively often to preventable AEs (93%) and AEs resulting in permanent disability (20%). Recommended strategies to prevent AEs were quality assurance/peer review, evaluation of safety behaviour, training and procedures. For the AEs with human and patient-related causes, reviewers predominantly recommended quality assurance/peer review. AEs caused by organisational factors were considered preventable by improving procedures. Discussion Healthcare interventions directed at human causes are recommended because these play a large role in AE causation. In addition, it seems worthwhile to direct interventions on organisational causes because the AEs they cause are nearly always believed to be preventable. Organisational factors are thus relatively easy to tackle. Future research designs should allow researchers to interview healthcare providers that were involved in the event, as an additional source of information on contributing factors.

Relating faults in diagnostic reasoning with diagnostic errors and patient harm.

Purpose The relationship between faults in diagnostic reasoning, diagnostic errors, and patient harm has hardly been studied. This study examined suboptimal cognitive acts (SCAs; i.e., faults in diagnostic reasoning), related them to the occurrence of diagnostic errors and patient harm, and studied the causes. Method Four expert internists reviewed patient records of 247 dyspnea patients, using a specially developed questionnaire to detect SCAs. The patients were treated by 72 physicians between May 2007 and February 2008 in five Dutch hospitals. The findings of the record review were discussed with the treating physicians, and the causes of SCAs were classified using Reasons taxonomy of unsafe acts. Statistical analyses were performed with descriptive statistics and independent t tests to compare groups. Furthermore, a reliability study was conducted to assess the interrater reliability. Results SCAs occurred in 163 of 247 cases reviewed (66%). In 34 (13.8%) of all cases, a diagnostic error occurred, and in 28 (11.3%) cases, the patient was harmed. Cases with diagnostic errors or patient harm had more SCAs. However, in 10 (4.0%) of the cases, diagnostic errors or patient harm occurred, though there were no SCAs. The causes of SCAs were mostly mistakes (i.e., the planned action was incorrect). Conclusions In cases with more SCAs, diagnostic errors and patient harm occurred more often, suggesting that the number of SCAs per case was predictive of the occurrence of these events. The most common causes were mistakes, meaning that physicians did not realize their actions were incorrect.

The challenges in defining and measuring diagnostic error

Abstract Diagnostic errors have emerged as a serious patient safety problem but they are hard to detect and complex to define. At the research summit of the 2013 Diagnostic Error in Medicine 6th International Conference, we convened a multidisciplinary expert panel to discuss challenges in defining and measuring diagnostic errors in real-world settings. In this paper, we synthesize these discussions and outline key research challenges in operationalizing the definition and measurement of diagnostic error. Some of these challenges include 1) difficulties in determining error when the disease or diagnosis is evolving over time and in different care settings, 2) accounting for a balance between underdiagnosis and overaggressive diagnostic pursuits, and 3) determining disease diagnosis likelihood and severity in hindsight. We also build on these discussions to describe how some of these challenges can be addressed while conducting research on measuring diagnostic error.

Advancing the research agenda for diagnostic error reduction

Diagnostic errors remain an underemphasised and understudied area of patient safety research. We briefly summarise the methods that have been used to conduct research on epidemiology, contributing factors and interventions related to diagnostic error and outline directions for future research. Research methods that have studied epidemiology of diagnostic error provide some estimate on diagnostic error rates. However, there appears to be a large variability in the reported rates due to the heterogeneity of definitions and study methods used. Thus, future methods should focus on obtaining more precise estimates in different settings of care. This would lay the foundation for measuring error rates over time to evaluate improvements. Research methods have studied contributing factors for diagnostic error in both naturalistic and experimental settings. Both approaches have revealed important and complementary information. Newer conceptual models from outside healthcare are needed to advance the depth and rigour of analysis of systems and cognitive insights of causes of error. While the literature has suggested many potentially fruitful interventions for reducing diagnostic errors, most have not been systematically evaluated and/or widely implemented in practice. Research is needed to study promising intervention areas such as enhanced patient involvement in diagnosis, improving diagnosis through the use of electronic tools and identification and reduction of specific diagnostic process ‘pitfalls’ (eg, failure to conduct appropriate diagnostic evaluation of a breast lump after a ‘normal’ mammogram). The last decade of research on diagnostic error has made promising steps and laid a foundation for more rigorous methods to advance the field.

Design of a study on suboptimal cognitive acts in the diagnostic process, the effect on patient outcomes and the influence of workload, fatigue and experience of physician

BackgroundDiagnostic error is an important error type since diagnostic adverse events are regularly judged as being preventable and the consequences are considered to be severe. Existing research often focuses on either diagnostic adverse events or on the errors in diagnostic reasoning. Whether and when an incorrect diagnostic process results in adverse outcomes has not been studied extensively. The present paper describes the design of a study that aims to study the relationship between a suboptimal diagnostic process and patient outcomes. In addition, the role of personal and circumstantial factors on the quality of the diagnostic process will be examined.Methods/DesignThe research questions were addressed using several data sources. First, the differential diagnosis was assessed concurrently to the diagnostic process. Second, the patient records of 248 patients suffering from shortness of breath were reviewed by expert internists in order to reveal suboptimal cognitive acts and (potential) consequences for the patient. The suboptimal cognitive acts were discussed with the treating physicians and classified with the taxonomy of unsafe acts. Third, workload, fatigue and work experience were measured during the physicians work. Workload and fatigue were measured during the physicians shift using the NASA tlx questionnaire on a handheld computer. Physicians participating in the study also answered questions about their work experience.DiscussionThe design used in this study provides insight into the relationship between suboptimal cognitive acts in the diagnostic process and possible consequences for the patient. Suboptimal cognitive acts in the diagnostic process and its causes can be revealed. Additional measurements of workload, fatigue and experience allow examining the influence of these factors on the diagnostic process. In conclusion, the present design provides a method with which insights in weaknesses of the diagnostic process and the effect on patient outcomes can be studied and opportunities for improvement can be obtained.

Does inappropriate selectivity in information use relate to diagnostic errors and patient harm? The diagnosis of patients with dyspnea

Physicians often take shortcuts in diagnostic reasoning by being selective in the information that they gather and follow-up on. Although necessary, these shortcuts are susceptible to cognitive biases and may cause diagnostic errors. The aim of this study is to examine the occurrence of inappropriate selectivity in the information-gathering and information-processing stages of the diagnostic process and study how it relates to diagnostic errors and patient harm in clinical practice. Expert internists reviewed the patient records of 247 dyspnea patients of five acute-care hospitals in the Netherlands, to detect reasoning faults, diagnostic errors and patient harm. The cases with reasoning faults were discussed with the treating physicians. Based on the record review and the clarifications from the treating physicians, the occurrence of inappropriate selectivity in information-gathering and information-processing was established and related to the occurrence of diagnostic errors and patient harm. Inappropriate selectivity in the diagnostic reasoning process occurred in 45.7% (113 of 247) of the cases. Specifically, selective information-gathering occurred in 33.2% of the cases and selective information-processing in 12.6% of the cases. Diagnostic errors occurred in 18.3% of the cases with selective information-gathering, and in 35.5% of the cases with selective information-processing. Patient harm occurred in 11.0% of the cases with selective information-gathering and in 38.7% of the cases with selective information-processing. The results showed that inappropriate selectivity in the diagnostic process occurred in a substantial number of cases. Particularly inappropriate selective information-processing was related to diagnostic errors and patient harm. Prevention strategies should include an increase in promoting the falsification strategies in the diagnostic process.

The nature and causes of unintended events reported at 10 internal medicine departments.

Objective This study aimed to examine the nature and causes of unintended events (UEs) at internal medicine departments (IMD). Methods An observational study was conducted at 10 IMDs in 8 Dutch hospitals. The study period per participating department was 5 to 14 weeks. During this period, staff were asked to report all UEs concerning patient safety. To identify underlying root causes, experienced researchers analyzed the reports using a standardized root cause analysis method called PRISMA medical. Results Hospital staff reported 625 UEs. Medication-related UEs were the most reported events (42%). Of all reported UEs, 12% involved the collaboration between the IMD and other departments within the hospital. On the basis of the 625 UEs, 920 root causes were identified. The mean (SD) number of root causes per incident was 1.47 (0.68). Human root causes were related to 83.2% of the UEs, organizational root causes were related to 15.7%, technical root causes were related to 7%, and other root causes were related to 8.6% of the UEs. More than half of the reported UEs reached the patient (62%), with suboptimal care as the most frequently occurring consequence (44.7%). Physical injury occurred in 10.3% of the UEs. Conclusions Hospital staff reporting UEs seems to be a good method for gaining insight into the types of UEs that occur at hospital departments. Although many UEs had human causes, identifying technical and organizational causes is important for the development of successful improvement strategies considering their contribution to human error. Important targets for these strategies are the medication process and collaboration within the hospital.

Unit-based incident reporting and root cause analysis: variation at three hospital unit types

Objectives To minimise adverse events in healthcare, various large-scale incident reporting and learning systems have been developed worldwide. Nevertheless, learning from patient safety incidents is going slowly. Local, unit-based reporting systems can help to get faster and more detailed insight into unit-specific safety issues. The aim of our study was to gain insight into types and causes of patient safety incidents in hospital units and to explore differences between unit types. Design Prospective observational study. Setting 10 emergency medicine units, 10 internal medicine units and 10 general surgery units in 20 hospitals in the Netherlands participated. Patient safety incidents were reported by healthcare providers. Reports were analysed with root cause analysis. The results were compared between the 3 unit types. Results A total of 2028 incidents were reported in an average reporting period of 8 weeks per unit. More than half had some consequences for patients, such as a prolonged hospital stay or longer waiting time, and a small number resulted in patient harm. Significant differences in incident types and causes were found between unit types. Emergency units reported more incidents related to collaboration, whereas surgical and internal medicine units reported more incidents related to medication use. The distribution of root causes of surgical and emergency medicine units showed more mutual similarities than those of internal medicine units. Conclusions Comparable incidents and causes have been found in all units, but there were also differences between units and unit types. Unit-based incident reporting gives specific information and therefore makes improvements easier. We conclude that unit-based incident reporting has an added value besides hospital-wide or national reporting systems that already exist in various countries.