[Analysis of the major clinical-pathological discrepancies in autopsies of adults in a tertiary referral hospital between 2008-2017]. / Análisis de las principales discrepancias clínico-patológicas mayores en adultos en los estudios de autopsia de un hospital de tercer nivel en la década 2008-2017.

OBJECTIVE: To compare and contrast clinical diagnoses with autopsy findings in order to identify unexpected, relevant discrepancies. MATERIAL AND METHOD: A retrospective observational study of the revision of autopsies of adults and their respective medical records in order to classify them according to referral department and Goldman's classification was carried out at the Central University Hospital of Asturias between 2008-2017. RESULTS: 694 (52.6%) of 1320 autopsies were included in the study. Discrepancies were observed in 57.6% of cases, although the majority (39.3%) were minor. Type I discrepancies were identified in 63 autopsies (9.1%); malignant neoplasms being the main pathology observed (57.1%), mainly of gastrointestinal origin (about 28%). The second most common discrepancy was found in cases of infectious diseases (23.8%) followed by pulmonary embolism (15.9%). 64 autopsies were classified as type II discrepancies (9.2%), with myocardial infarct the most common (37.5%), especially acute myocardial infarction (18 cases), followed by bronchoaspirations (18.7%), DIC (15.6%), massive haemorrhages (9.4%) and other conditions. It was considered that both the ICU and the Internal Medicine Service were responsible for the largest number of major discrepancies (type I and II), accounting for about 45% of type I and slightly more than 56% for type II. CONCLUSION: Autopsies are an essential means of identifying ante-mortem clinical errors. The incidence of major discrepancies in the Central University Hospital of Asturias (18.3%) is comparable to that of leading hospitals worldwide.

Stroke Mimics and Chameleons from the Radiological Viewpoint of Glioma Diagnosis.

Gliomas are sometimes difficult to differentiate from strokes and are often misdiagnosed on magnetic resonance imaging (MRI); thus, the terms "stroke mimics" and "stroke chameleons" have been introduced. In this study, we analyzed stroke mimics and stroke chameleons in glioma and discussed the diagnostic perplexity.We retrospectively reviewed cases that were removed from lesions that were considered to be brain tumors. This study enrolled 214 patients who underwent tumor resection for suspected glioma. Clinical characteristics and radiological findings of the patients were compared between the masquerade findings group, which was further divided into two groups: the stroke chameleons and stroke mimics according to their final diagnosis, and the intelligible findings group.Stroke chameleons and stroke mimics were significantly higher in age and smaller in lesion size than the intelligible findings group. In the multivariate analysis, the predictive factor of the masquerade finding group was higher age and smaller size. Stroke mimics group has a tendency to be higher rate of hyperintensity lesion on diffusion-weighted imaging (DWI) compared with stroke chameleons group. The average period from initial diagnosis to pathological diagnosis was 13.50 days in the stroke chameleons and 61.50 days in the stroke mimics, which proved significantly different.Proper diagnosis of glioma and stroke affects a patient's prognosis, and should be diagnosed as soon as possible. However, stroke mimics and stroke chameleons caused by glioma can occur. Thus, the diagnosis of a stroke should take into consideration the possibility of a glioma in real clinical situations.

Anterior Urethral Valve - A Commonly Misdiagnosed Entity in Adolescent Boys.

Anterior urethral valves are a rare cause of obstructed voiding in adolescent children and are often unheard by adult urologists. In this case report, we discuss the management of two adolescent patients who were referred to us with obstructive voiding symptoms with a diagnosis of neurogenic bladder and posterior urethral valves respectively but on evaluation were found to have anterior urethral valves. This article highlights the need for considering anterior urethral valve as an important differential diagnosis in children and adolescents presenting with obstructive voiding symptoms so as to avoid delay in diagnosis and management in young boys.

Misdiagnosis and diagnostic delay in non-paraneoplastic sensory neuronopathies.

METHODS: Sensory neuronopathies (SN) are a group of peripheral nerve disorders characterized by multifocal non-length-dependent sensory deficits and sensory ataxia. Its recognition is essential not only for proper management but also to guide the etiological investigation. The uncommon SN clinical picture and its rarity set the conditions for the misdiagnosis and the diagnostic delay, especially in non-paraneoplastic SN. Therefore, our objectives were to characterize the diagnostic odyssey for non-paraneoplastic SN patients, as well as to identify possible associated factors. We consecutively enrolled 48 non-paraneoplastic SN patients followed in a tertiary neuromuscular clinic at the University of Campinas (Brazil). All patients were instructed to retrieve their previous medical records, and we collected the data regarding demographics, disease onset, previous incorrect diagnoses made and the recommended treatments. RESULTS: There were 34 women, with a mean age at the diagnosis of 45.9 ± 12.2 years, and 28/48 (58%) of the patients were idiopathic. Negative sensory symptoms were the heralding symptoms in 25/48 (52%); these were asymmetric in 36/48 (75%) and followed a chronic course in 35/48 (73%). On average, it took 5.4 ± 5.3 years for SN to be diagnosed; patients had an average of 3.4 ± 1.5 incorrect diagnoses. A disease onset before the age of 40 was associated to shorter diagnosis delay (3.7 ± 3.4 vs. 7.8 ± 6.7 years, p = 0.01). CONCLUSIONS: These results suggest that diagnostic delay and misdiagnosis are frequent in non-paraneoplastic SN patients. As in other rare conditions, increased awareness in all the healthcare system levels is paramount to ensure accurate diagnosis and to improve care of these patients.

Misdiagnosis and diagnostic delay in non-paraneoplastic sensory neuronopathies / Erro e atraso diagnóstico nas neuronopatias sensitivas não paraneoplásicas

ABSTRACT Sensory neuronopathies (SN) are a group of peripheral nerve disorders characterized by multifocal non-length-dependent sensory deficits and sensory ataxia. Its recognition is essential not only for proper management but also to guide the etiological investigation. The uncommon SN clinical picture and its rarity set the conditions for the misdiagnosis and the diagnostic delay, especially in non-paraneoplastic SN. Therefore, our objectives were to characterize the diagnostic odyssey for non-paraneoplastic SN patients, as well as to identify possible associated factors. Methods We consecutively enrolled 48 non-paraneoplastic SN patients followed in a tertiary neuromuscular clinic at the University of Campinas (Brazil). All patients were instructed to retrieve their previous medical records, and we collected the data regarding demographics, disease onset, previous incorrect diagnoses made and the recommended treatments. Results There were 34 women, with a mean age at the diagnosis of 45.9 ± 12.2 years, and 28/48 (58%) of the patients were idiopathic. Negative sensory symptoms were the heralding symptoms in 25/48 (52%); these were asymmetric in 36/48 (75%) and followed a chronic course in 35/48 (73%). On average, it took 5.4 ± 5.3 years for SN to be diagnosed; patients had an average of 3.4 ± 1.5 incorrect diagnoses. A disease onset before the age of 40 was associated to shorter diagnosis delay (3.7 ± 3.4 vs. 7.8 ± 6.7 years, p = 0.01). Conclusions These results suggest that diagnostic delay and misdiagnosis are frequent in non-paraneoplastic SN patients. As in other rare conditions, increased awareness in all the healthcare system levels is paramount to ensure accurate diagnosis and to improve care of these patients.

RESUMO As neuronopatias sensitivas (NS) representam um grupo de doenças caracterizadas por ataxia sensitiva e déficits sensitivos multifocais e não-comprimento dependentes. O seu reconhecimento é fundamental para o tratamento apropriado e para a investigação de doenças associadas. O quadro clínico pouco frequente aliado à baixa prevalência, especialmente das formas não-paraneoplásicas (NSnp), colaboram para o atraso e erro no diagnóstico. Os objetivos desse trabalho são descrever a odisseia diagnóstica dos pacientes com NSnp e tentar identificar possíveis fatores associados. Métodos Foram incluídos consecutivamente 48 pacientes com NSnp acompanhados no ambulatório de doenças neuromusculares da Universidade Estadual de Campinas (Brasil). Dados demográficos e sobre o início da NS (incluindo diagnósticos que lhes foram dados e tratamentos prescritos) foram coletados. Resultados Na coorte descrita havia 34 mulheres e a idade ao diagnóstico era de 45,9 ± 12,2 anos. Os sintomas inaugurais eram sensitivos deficitários em 25/48 (52%) dos pacientes, sendo assimétricos em 36/48 (75%) e de evolução crônica em 35/48 (73%). Para 28/48 (58%) dos pacientes a NS era idiopática. Em média, os pacientes com NSnp tiveram um atraso diagnóstico de 5,4 ± 5,3 anos com uma média de 3,4 ± 1,5 diagnósticos incorretos. Pacientes com início antes dos 40 anos tiveram diagnóstico mais precoce que aqueles com início tardio (3,7 ± 3,4 vs. 7,8 ± 6,7 anos, p = 0,01). Conclusão Os dados ora apresentados sugerem que o erro e o atraso diagnóstico são frequentes e impactam os pacientes com NS. A importância do diagnóstico das NS deve ser constante em todos os níveis do sistema de saúde para o diagnóstico correto e a consequente melhora no cuidado a esses pacientes.

Spectrum of diagnostic errors in cervical spine trauma imaging and their clinical significance.

PURPOSE: To describe and categorize diagnostic errors in cervical spine CT (CsCT) interpretation performed for trauma and to assess their clinical significance. METHODS: All CsCTs performed for trauma with diagnostic errors that came to our attention based on clinical or imaging follow-up or quality assurance peer review from 2004 to 2017 were included. The number of CsCTs performed at our institution during the same time interval was calculated. Errors were categorized as spinal/extraspinal, involving osseous/soft tissue structures, by anatomical site and level. Images were reviewed by a radiologist and two spine surgeons. For each error, the need for surgery, immobilization, CT angiogram of the neck, and MRI was assessed; if any of these were needed, the error was considered clinically significant. RESULTS: Of an approximate total 59,000 CsCTs, 56 reports containing diagnostic errors were included. Twelve were extraspinal, and 44 were spinal (26 fractures, 15 intervertebral disc protrusions, two subluxations, one lytic bone lesion). The most common sites of spinal fractures were vertebral body (n = 10) and transverse process (n = 8); the most common levels were C5 (n = 8) and C7 (n = 6). All (n = 26) fractures and two atlantooccipital subluxations were considered clinically significant, including three patients who would have required urgent surgical stabilization (two subluxations and one facet fracture). Two transverse processes fractures did not alter the need for surgical intervention/surgical approach, immobilization, or MRI. CONCLUSIONS: In our study, 66% of spinal diagnostic errors on CsCT were considered clinically significant, potentially altering clinical management. Transverse process and vertebral body fractures were commonly missed.

Diagnostic Error Categorization at Abdominal Imaging Peer Learning Conference.

Recognizing and preventing diagnostic errors is an increasingly emphasized topic across medicine, and abdominal imaging is no exception. Peer-learning strives for quality improvement through understanding why errors occur and identifying opportunities to prevent errors from recurring. In an effort to learn from mistakes, our abdominal imaging section initiated a Peer Learning Conference, where errors are discussed and compartmentalized into one or more of the following categories: Observation, Interpretation, Communication, and Inadequate Data Gathering. In this manuscript, the structure of our Peer Learning Conference is introduced and the components of each discrepancy category are described in detail. Images are included to highlight learning points through exemplary cases from the conference.

Diagnostic Errors in Tuberculous Patients: A Multicenter Study from a Developing Country.

Although there is still much to learn about the types of errors committed in health care and why they occur, enough is known today to recognize that a serious concern exists for patients. Tuberculosis (TB) is an infectious disease that is frequently subject to diagnostic errors. Missed or delayed diagnosis of TB can affect patients and community adversely. Our aim in the present study was at evaluating the type of diagnostic errors in TB patients from symptom onset to diagnosis. This was a multicenter cross-sectional study conducted in three university hospitals in Mashhad, Iran. We showed a long delay in diagnosing TB that is mostly related to the time from first medical visit to diagnosis. Errors in the diagnostic process were identified in 97.5% of patients. The most common type of error in diagnosing TB was failure in hypothesis generation (72%), followed by history taking and physical examination. In conclusion, it seems likely that efforts to improve public awareness of and health literacy for TB, to coordinate the referral and follow-up systems of patients, and to improve physicians' skills in history taking and physical examination and clinical reasoning will result in reduced delay in diagnosis of TB and, perhaps, improved patient safety and community health.

Identifying error types in visual diagnostic skill assessment.

BACKGROUND: Misinterpretation of medical images is an important source of diagnostic error. Errors can occur in different phases of the diagnostic process. Insight in the error types made by learners is crucial for training and giving effective feedback. Most diagnostic skill tests however penalize diagnostic mistakes without an eye for the diagnostic process and the type of error. A radiology test with stepwise reasoning questions was used to distinguish error types in the visual diagnostic process. We evaluated the additional value of a stepwise question-format, in comparison with only diagnostic questions in radiology tests. METHODS: Medical students in a radiology elective (n=109) took a radiology test including 11-13 cases in stepwise question-format: marking an abnormality, describing the abnormality and giving a diagnosis. Errors were coded by two independent researchers as perception, analysis, diagnosis, or undefined. Erroneous cases were further evaluated for the presence of latent errors or partial knowledge. Inter-rater reliabilities and percentages of cases with latent errors and partial knowledge were calculated. RESULTS: The stepwise question-format procedure applied to 1351 cases completed by 109 medical students revealed 828 errors. Mean inter-rater reliability of error type coding was Cohen's κ=0.79. Six hundred and fifty errors (79%) could be coded as perception, analysis or diagnosis errors. The stepwise question-format revealed latent errors in 9% and partial knowledge in 18% of cases. CONCLUSIONS: A stepwise question-format can reliably distinguish error types in the visual diagnostic process, and reveals latent errors and partial knowledge.

Ex Vivo Artifacts and Histopathologic Pitfalls in the Lung.

CONTEXT: Surgical and pathologic handling of lung physically affects lung tissue. This leads to artifacts that alter the morphologic appearance of pulmonary parenchyma. OBJECTIVE: To describe and illustrate mechanisms of ex vivo artifacts that may lead to diagnostic pitfalls. DESIGN: In this study 4 mechanisms of ex vivo artifacts and corresponding diagnostic pitfalls are described and illustrated. RESULTS: The 4 patterns of artifacts are: (1) surgical collapse, due to the removal of air and blood from pulmonary resections; (2) ex vivo contraction of bronchial and bronchiolar smooth muscle; (3) clamping edema of open lung biopsies; and (4) spreading of tissue fragments and individual cells through a knife surface. Morphologic pitfalls include diagnostic patterns of adenocarcinoma, asthma, constrictive bronchiolitis, and lymphedema. CONCLUSION: Four patterns of pulmonary ex vivo artifacts are important to recognize in order to avoid morphologic misinterpretations.

Overdiagnosis of idiopathic intracranial hypertension.

OBJECTIVE: To delineate the factors contributing to overdiagnosis of idiopathic intracranial hypertension (IIH) among patients seen in one neuro-ophthalmology service at a tertiary center. METHODS: We retrospectively reviewed new patients referred with a working diagnosis of IIH over 8 months. The Diagnosis Error Evaluation and Research taxonomy tool was applied to cases referred with a diagnosis of IIH and a discrepant final diagnosis. RESULTS: Of 1,249 patients, 165 (13.2%) were referred either with a preexisting diagnosis of IIH or to rule out IIH. Of the 86/165 patients (52.1%) with a preexisting diagnosis of IIH, 34/86 (39.5%) did not have IIH. The most common diagnostic error was inaccurate ophthalmoscopic examination in headache patients. Of 34 patients misdiagnosed as having IIH, 27 (27/34 [79.4%]; 27/86 [31.4%]) had at least one lumbar puncture, 29 (29/34 [85.3%]; 29/86 [33.7%]) had a brain MRI, and 8 (8/34 [23.5%]; 8/86 [9.3%]) had a magnetic resonance/CT venogram. Twenty-six had received medical treatment, 1 had a lumbar drain, and 4 were referred for surgery. In 8 patients (8/34 [23.5%]; 8/86 [9.3%]), an alternative diagnosis requiring further evaluation was identified. CONCLUSIONS: Diagnostic errors resulted in overdiagnosis of IIH in 39.5% of patients referred for presumed IIH, and prompted unnecessary tests, invasive procedures, and missed diagnoses. The most common errors were inaccurate ophthalmoscopic examination in headache patients and thinking biases, reinforcing the need for rapid access to specialists with experience in diagnosing optic nerve disorders. Indeed, the high prevalence of primary benign headaches and obesity in young women often leads to costly and invasive evaluations for presumed IIH.

Application of a human factors classification framework for patient safety to identify precursor and contributing factors to adverse clinical incidents in hospital.

This study aimed to identify temporal precursor and associated contributing factors for adverse clinical incidents in a hospital setting using the Human Factors Classification Framework (HFCF) for patient safety. A random sample of 498 clinical incidents were reviewed. The framework identified key precursor events (PE), contributing factors (CF) and the prime causes of incidents. Descriptive statistics and correspondence analysis were used to examine incident characteristics. Staff action was the most common type of PE identified. Correspondence analysis for all PEs that involved staff action by error type showed that rule-based errors were strongly related to performing medical or monitoring tasks or the administration of medication. Skill-based errors were strongly related to misdiagnoses. Factors relating to the organisation (66.9%) or the patient (53.2%) were the most commonly identified CFs. The HFCF for patient safety was able to identify patterns of causation for the clinical incidents, highlighting the need for targeted preventive approaches, based on an understanding of how and why incidents occur.

JOURNAL CLUB: Radiology Report Addenda: A Self-Report Approach to Error Identification, Quantification, and Classification.

OBJECTIVE: The purpose of this study was to analyze report addenda to assess the self-reported error rate in radiologic study interpretation, the types of errors that occur, and the distribution of error by image modality. MATERIALS AND METHODS: Addenda to all diagnostic radiology reports were compiled over a 1-year period (n = 5568). The overall error rate was based on addenda frequency relative to the total number of studies performed. Addenda written over the most recent 2-month interval (n = 851) were classified into five major categories of predominant error type: underreading, overreading, poor communication, insufficient history, and poor technique. Each category was further divided into multiple subtypes. RESULTS: Diagnostic studies at our hospital had an error rate of 0.8%. Errors of poor communication occurred most frequently (44%), followed by underreading (7%), insufficient history (21%), overreading (8%), and poor technique (1%). Analyzed by imaging modality, most errors occurred in PET (19.45 per 1000 studies), followed by MRI (13.86 per 1000 studies) and CT (12.45 per 1000 studies). CONCLUSION: Through the use of report addenda to calculate error, discrepancy between individual radiologists is removed in a reproducible and widely applicable way. This approach to error typology eliminates sample bias and in a departure from previous analyses of difficult cases shows that errors of communication are most frequent, representing a clear area for targeted improvement.

A system dynamics approach to analyze laboratory test errors.

Although many researches have been carried out to analyze laboratory test errors during the last decade, it still lacks a systemic view of study, especially to trace errors during test process and evaluate potential interventions. This study implements system dynamics modeling into laboratory errors to trace the laboratory error flows and to simulate the system behaviors while changing internal variable values. The change of the variables may reflect a change in demand or a proposed intervention. A review of literature on laboratory test errors was given and provided as the main data source for the system dynamics model. Three "what if" scenarios were selected for testing the model. System behaviors were observed and compared under different scenarios over a period of time. The results suggest system dynamics modeling has potential effectiveness of helping to understand laboratory errors, observe model behaviours, and provide a risk-free simulation experiments for possible strategies.

Diagnostic Errors in a PICU: Insights From the Morbidity and Mortality Conference.

OBJECTIVES: To describe diagnostic errors identified among patients discussed at a PICU morbidity and mortality conference in terms of Goldman classification, medical category, severity, preventability, contributing factors, and occurrence in the diagnostic process. DESIGN: Retrospective record review of morbidity and mortality conference agendas, patient charts, and autopsy reports. SETTING: Single tertiary referral PICU in Baltimore, MD. PATIENTS: Ninety-six patients discussed at the PICU morbidity and mortality conference from November 2011 to December 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Eighty-nine of 96 patients (93%) discussed at the PICU morbidity and mortality conference had at least one identified safety event. A total of 377 safety events were identified. Twenty patients (21%) had identified misdiagnoses, comprising 5.3% of all safety events. Out of 20 total diagnostic errors identified, 35% were discovered at autopsy while 55% were reported primarily through the morbidity and mortality conference. Almost all diagnostic errors (95%) could have had an impact on patient survival or safety. Forty percent of errors did not cause actual patient harm, but 25% were severe enough to have potentially contributed to death (40% no harm vs 35% some harm vs 25% possibly contributed to death). Half of the diagnostic errors (50%) were rated as preventable. There were slightly more system-related factors (40%) solely contributing to diagnostic errors compared with cognitive factors (20%); however, 35% had both system and cognitive factors playing a role. Most errors involved vascular (35%) followed by neurologic (30%) events. CONCLUSIONS: Diagnostic errors in the PICU are not uncommon and potentially cause patient harm. Most appear to be preventable by targeting both cognitive- and system-related contributing factors. Prospective studies are needed to further determine how and why diagnostic errors occur in the PICU and what interventions would likely be effective for prevention.

Identifying errors and inconsistencies in real time while using facilitated echocardiographic reporting.

BACKGROUND: Facilitated reporting using a discrete set of finding codes (FCs) is a common method of generating echocardiographic reports. METHODS: The investigators developed a tool that allows echocardiographic reports to be evaluated in real time for errors, omissions, and inconsistencies on the basis of a defined group of "rules" applied to the FCs present in the report. At the time of report finalization, conflicts were displayed for the interpreting physicians, and their responses to each rule conflict were logged. RESULTS: Over the course of 1 year, 7,986 transthoracic echocardiographic reports were analyzed prospectively during study interpretation. Overall, 30 ± 4.7 FCs were used to generate finalized reports. An average of 2.4 ± 2.0 conflicts were detected per finalized study. Eighty-three percent of studies had at least one conflict identified. There was no significant correlation between physician experience and conflict rates, but time of day (earlier) and rate at which studies were being finalized (faster) were both correlated with increased conflict rate. Overall, physicians ignored identified conflicts 52% of the time and altered their readings to eliminate the conflicts 48% of the time. Overall, at least one change was made in 54% of all finalized studies. There was a small but significant trend for physicians to produce more conflicts over time as the tool was used. CONCLUSIONS: This study demonstrates that facilitated reporting of echocardiographic studies, using a discrete set of FCs, allows the generation of rules that can be used to identify discrepancies in echocardiographic reports before finalization. Conflicts are common in clinical practice, and the identification of these conflicts in real time allowed readers to review their interpretations and frequently resulted in alterations to echocardiographic reports.

Value of a standardized lexicon for reporting levels of diagnostic certainty in prostate MRI.

OBJECTIVE: The purpose of this study was to evaluate the usefulness and diagnostic performance of a 5-point standardized diagnostic certainty lexicon for reporting the likelihood of extracapsular extension (ECE) of prostate cancer on routine staging prostate MRI. MATERIALS AND METHODS: This study was a retrospective analysis of routine clinical prostate MRI reports before (254 patients) and after (211 patients) the implementation of a 5-point diagnostic certainty lexicon. Whole-mount step-section pathology of the radical prostatectomy specimens served as the reference standard. The terms used to express diagnostic certainty regarding ECE on standard-of-care MRI and the presence of ECE on pathology were compared between the two periods. ROC analysis was used to evaluate the diagnostic accuracy of the 5-point certainty lexicon for detecting ECE. RESULTS: Before the implementation of the certainty lexicon, radiologists used 38 different terms to express the levels of certainty regarding the presence of ECE on MRI. Afterward, they adhered to the lexicon's predefined 5-point terminology in 85.3% of cases. The 5-point certainty lexicon used on MRI reports had an AUC of 0.852 for diagnosing ECE. CONCLUSION: The implementation of a lexicon of diagnostic certainty dramatically reduced the number of expressions used by radiologists to indicate their levels of diagnostic certainty. The accuracy of the certainty lexicon for diagnosing ECE on standard-of-care prostate MRI is similar to previously reported accuracy values for the diagnosis of ECE by MRI. Thus, the use of such a lexicon might prevent miscommunication and help referring clinicians reliably incorporate radiologists' assessments into clinical decision making.

A causal loop approach to the study of diagnostic errors.

Missed, wrong or delayed diagnosis has a direct effect on patient safety. Diagnostic errors have been discussed at length, however it still lacks a systematic approach. This study proposed a more systematic way of studying diagnostic errors by using a causal loop diagram. A systematic review was used to find the key factors which may cause diagnostic errors and their interrelationships. A causal loop diagram, as a qualitative model at the first stage of system dynamics modeling, was produced to map all the factor and interrelationships. The diagram provides not only the direct and indirect factors affecting correct diagnosis, but also a clear view of how the change of one factor in the model triggers changes of other factors and then the change of the number of final diagnostic errors.