The Measurement of Performance in Probabilistic Diagnosis

Owing to the inherent uncertainty of diagnostic tasks, diagnostic advice should be offered in a probabilistic, rather than deterministic form. Since the late fifties a lot of effort has been invested in constructing probabilistic diagnosis rules. Much less has been done to devise rational tools for evaluating them ; conventional error rates reflect but one aspect of performance in a rather crude way. The aim of this paper and its successors is to offer a body of evaluation tools. After defining a general framework and stating its limitations we apply some graphical techniques to the acute abdominal pain data that will serve as illustration in the next papers as well: dot diagrams, the triangular diagram for the three-disease case, and three tabular representations based on categorization of the probabilities, viz. the usual (forced) classification matrix, from which various classification rates are read off; the classification matrix with doubt, in which uncertain and confident diagnoses are distinguished; and the exclusion matrix, which spots diseases that are judged improbable. Together these matrices give a good first impression of the behaviour of a probabilistic diagnosis system. The outlined techniques of later papers are needed for a more complete analysis.

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The Measurement of Performance in Probabilistic Diagnosis

Methods of Information in Medicine ◽

10.1055/s-0038-1636441 ◽

1978 ◽

Vol 17 (04) ◽

pp. 217-226

Author(s):

J. D. F. Habbbma ◽

J. Hilden ◽

B. Bjerregaard

Keyword(s):

Abdominal Pain ◽

General Framework ◽

Acute Abdominal Pain ◽

Error Rates ◽

Complete Analysis ◽

Evaluation Tools ◽

Triangular Diagram ◽

Disease Case ◽

First Impression ◽

Probabilistic Diagnosis

Owing to the inherent uncertainty of diagnostic tasks, diagnostic advice should be offered in a probabilistic, rather than deterministic form. Since the late fifties a lot of effort has been invested in constructing probabilistic diagnosis rules. Much less has been done to devise rational tools for evaluating them; conventional error rates reflect but one aspect of performance in a rather crude way. The aim of this paper and its successors is to offer a body of evaluation tools. After defining a general framework and stating its limitations we apply some graphical techniques to the acute abdominal pain data that will serve as illustration in the next papers as well: dot diagrams, the triangular diagram for the three-disease case, and three tabular representations based 011 categorization of the probabilities, viz. the usual (forced) classification matrix, from which various classification rates are read off; the classification matrix with doubt, in which uncertain and confident diagnoses are distinguished; and the exclusion matrix, which spots diseases that are judged improbable. Together these matrices give a good first impression of the behaviour of a probabilistic diagnosis system. The outlined techniques of later papers are needed for a more complete analysis.

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Tlie Measurement of Performance in Probabilistic Diagnosis

Methods of Information in Medicine ◽

10.1055/s-0038-1636443 ◽

1978 ◽

Vol 17 (04) ◽

pp. 238-246 ◽

Cited By ~ 87

Author(s):

J. Hilden ◽

J. D. F. Habbema ◽

B. Bjerregaard

Keyword(s):

Abdominal Pain ◽

Acute Abdominal Pain ◽

Continuous Functions ◽

Error Rates ◽

Scoring Rules ◽

Evaluation Tools ◽

Discriminatory Ability ◽

Scoring Rule ◽

Probability Prediction ◽

Probabilistic Diagnosis

Within the framework of diagnostic probability prediction the problem of measuring discriminatory ability is operationally defined as the problem of measuring the agreement between probabilistic predictions and actual outcomes. We present a number of so-called scoring rules developed to this end. Most of these are continuous functions of the assigned probabilities. Discontinuous rules, including conventional non-error rates, are discussed by way of contrast. The concept of properness of a scoring-rule is discussed and the desirability of properness is argued. Separate sections deal with the problems connected with uncommon diseases and methods utilizing subdivisions of the patient material. The distinction between the three concepts of discriminatory ability, sharpness and reliability is explained. The evaluation tools developed are applied to previously presented data from the Copenhagen Acute Abdominal Pain Study.

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EP.FRI.376 Early Routine CT Scans for All Surgical Admissions for Abdominal Pain May Improve Patient Outcomes

British Journal of Surgery ◽

10.1093/bjs/znab312.064 ◽

2021 ◽

Vol 108 (Supplement_7) ◽

Author(s):

Samantha Quah ◽

Hock Ping Cheah ◽

Kenneth Wong

Keyword(s):

Abdominal Pain ◽

Patient Outcomes ◽

Acute Abdominal Pain ◽

Correct Diagnosis ◽

Diagnostic Error ◽

Error Rates ◽

Accurate Diagnosis ◽

Diagnostic Challenge ◽

Radiology Report ◽

Imaging Results

Abstract Aim Acute abdominal pain remains a diagnostic challenge in the Emergency Department (ED) as pathologies can involve various surgical craft groups. Computed tomography (CT) enables accurate diagnosis of abdominal pathologies. However, with pressures on ED such as the “4 hour rule” established by the Australian NSW Health Emergency Performance Plan, there may be resistance or omission of early CT in ED. We hypothesise that early, routine CT in adult patients presenting with acute abdominal pain requiring hospital admission improves patient outcomes by increasing diagnostic and referral accuracy. This study compares the proportion of correct ED diagnosis of abdominal pain presentations with and without formal imaging reports. Methods Data from 118 patients presenting with abdominal pain are collected prospectively in a regional hospital and analysed. Patient demographics, imaging results, initial ED diagnosis and final discharge diagnosis are further examined. Results Out of the 118 patients who had abdominal pain, 32 patients obtained complete imaging with a radiology report whilst 86 patients either did not have any imaging performed or was referred to a general surgical unit prior to obtaining a formal report. Among the patients who had imaging reported, 78% (n = 25/32) had the correct diagnosis, whilst those without a radiology report had a 52% (n = 45/86) diagnostic accuracy. This demonstrates an improved accuracy of diagnosis or reduced error rate of 26% when a scan report is available (p = 0.01). Conclusion Early, routine CT with formal reporting significantly reduces diagnostic error rates and increases accurate referral. This allows accurate diagnosis and improves patient outcomes.

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Tratamiento quirúrgico conservador en un paciente con invaginación yeyuno-yeyunal secundaria a síndrome de Peutz-Jeghers. Reporte de un caso

Acta Pediátrica de México ◽

10.18233/apm39no3pp244-2491615 ◽

2018 ◽

Vol 39 (3) ◽

pp. 244

Author(s):

Rodrigo Ugalde Resano ◽

Irina Jeanette Bercholc Urinowsky ◽

Luis Enrique Escalona Ramírez ◽

Juan Miguel Blanco Torres ◽

Miguel Ángel Paz Muñoz ◽

...

Keyword(s):

Abdominal Pain ◽

Acute Abdominal Pain ◽

Clinical Manifestations ◽

Lower Lip ◽

Short Bowel ◽

Intestinal Intussusception ◽

Disease Case ◽

Patient Reported ◽

Peutz Jeghers Syndrome ◽

Intestinal Obstructions

INTRODUCCIÓN: el síndrome de Peutz-Jeghers es una enfermedad autosómica dominante, poco frecuente, caracterizada por hiperpigmentación mucocutánea y pólipos gastrointestinales; estos últimos causantes de obstrucciones intestinales recurrentes, secundarias a invaginación.PRESENTACIÓN DEL CASO: adolescente femenina, de 13 años, que acudió a urgencias debido a un cuadro de dolor abdominal intenso, con un cuadro de obstrucción intestinal secundario a invaginación yeyuno-yeyunal. Siete años antes tuvo un cuadro clínico similar que desapareció espontáneamente. A la exploración física se observaron lesiones hiperpigmentadas en el labio inferior y anemia microcítica e hipocrómica con los que se integró el diagnóstico de síndrome de Peutz-Jeghers. Debido a que en la tomografía axial computada de abdomen se evidenció invaginación intestinal se realizó una laparotomía exploradora, con el hallazgo de dos pólipos hamartomatosos de 2 y 3 cm de diámetro a 15 cm del ligamento de Treitz. Se trató la invaginación intestinal y, posteriormente, se efectuaron enterotomía y polipectomía. Mediante enteroscopia transoperatoria se descartaron otras alteraciones. Luego de tratar el cuadro clínico la paciente fue dada de alta del hospital en buenas condiciones. CONCLUSIÓN: la invaginación intestinal en adolescentes es una situación excepcional que requiere un alto índice de sospecha para enfermedades polipósicas. Se reporta un caso de invaginación intestinal que se trató existosamente con cirugía conservadora, sin necesidad de resecciones intestinales que, a largo plazo, condicionan síndrome de intestino corto: uno de los principales problemas a los que se enfrentan esto pacientes. PALABRAS CLAVE: Peutz-Jeghers, pólipos gastrointestinales, obstrucción intestinal recurrente, dolor abdominal agudo, yeyuno-yeyunal, adolescentes. Abstract INTRODUCTION: Peutz-Jeghers syndrome is an uncommon autosomal dominant disease, characterized by mucocutaneous hyperpigmentation and gastrointestinal polyps, which are the cause of recurrent intestinal obstructions, secondary to invagination. This case provides evidence to consider more conservative surgical treatments and prevent these patients from being constantly subjected to extensive bowel resections, which in many cases, can condition short bowel disease. CASE PRESENTATION: A 13-year-old female patient who came to the emergency room with acute abdominal pain due to intestinal obstruction secondary to jejuno-jejunal intussusception. 7 years ago, the patient reported similar clinical manifestations that solved spontaneously. Physical examination showed hyperpigmented lesions on the lower lip, and microcytic hypochromic anemia; Peutz-Jeghers syndrome was established. Intestinal intussusception was evidenced by computed axial tomography of the abdomen, so exploratory laparotomy was performed, with the finding of two hamartomatous polyps 2 and 3 cm in diameter at 15 cm of the Treitz ligament. Intestinal intussusception was resolved with subsequently, enterotomy and polypectomy. Other alterations were ruled out by trans-operative enteroscopy. At the resolution of clinical manifestations, the patient was discharged from the hospital in good clinical conditions. CONCLUSION: Intestinal intussusception in adolescents is an exceptional situation, which requires a high index of suspicion for polysposis diseases. We present a case of intestinal intussusception, successfully resolved with conservative surgical treatment, without requiring intestinal resections, which can condition short bowel syndrome in the long-term, one of the major problems these patients face. KEYWORDS: Peutz-Jeghers; gastrontestinal polyps; recurrent intestinal obstructions; acute abdominal pain; jejuno jejunal; adolescents.

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The Measurement of Performance in Probabilistic Diagnosis IV. Utility Considerations in Therapeutics and Prognostics

Methods of Information in Medicine ◽

10.1055/s-0038-1635297 ◽

1981 ◽

Vol 20 (02) ◽

pp. 80-96 ◽

Cited By ~ 32

Author(s):

J. D. F. Habbema ◽

J. Hilden

Keyword(s):

Decision Theory ◽

Figure Of Merit ◽

Acute Abdominal Pain ◽

Theory Approach ◽

Expected Loss ◽

Patient Benefit ◽

Evaluation Approach ◽

Average Loss ◽

Actual Decision ◽

Probabilistic Diagnosis

It is argued that it is preferable to evaluate probabilistic diagnosis systems in terms of utility (patient benefit) or loss (negative benefit). We have adopted the provisional strategy of scoring performance as if the system were the actual decision-maker (not just an aid to him) and argue that a rational figure of merit is given by the average loss which patients would incur by having the system decide on treatment, the treatment being selected according to the minimum expected loss principle of decision theory.A similar approach is taken to the problem of evaluating probabilistic prognoses, but the fundamental differences between treatment selection skill and prognostic skill and their implications for the assessment of such skills are stressed. The necessary elements of decision theory are explained by means of simple examples mainly taken from the acute abdomen, and the proposed evaluation tools are applied to Acute Abdominal Pain data analysed in our previous papers by other (not decision-theoretic) means. The main difficulty of the decision theory approach, viz. that of obtaining good medical utility values upon which the analysis can be based, receives due attention, and the evaluation approach is extended to cover more realistic situations in which utility or loss values vary from patient to patient.

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Bayesian Diagnostic Probabilities without Assuming Independence of Symptoms

Methods of Information in Medicine ◽

10.1055/s-0038-1634813 ◽

1991 ◽

Vol 30 (01) ◽

pp. 15-22 ◽

Cited By ~ 23

Author(s):

A. Gammerman ◽

A. R. Thatcher

Keyword(s):

Abdominal Pain ◽

Acute Abdominal Pain ◽

Final Diagnosis ◽

Bayes Theorem ◽

Bayes Method ◽

Hospital Records ◽

Computer Diagnosis ◽

Bayes Model ◽

Chi Squared ◽

Past Data

The paper describes an application of Bayes’ Theorem to the problem of estimating from past data the probabilities that patients have certain diseases, given their symptoms. The data consist of hospital records of patients who suffered acute abdominal pain. For each patient the records showed a large number of symptoms and the final diagnosis, to one of nine diseases or diagnostic groups. Most current methods of computer diagnosis use the “Simple Bayes” model in which the symptoms are assumed to be independent, but the present paper does not make this assumption. Those symptoms (or lack of symptoms) which are most relevant to the diagnosis of each disease are identified by a sequence of chi-squared tests. The computer diagnoses obtained as a result of the implementation of this approach are compared with those given by the “Simple Bayes” method, by the method of classification trees (CART), and also with the preliminary and final diagnoses made by physicians.

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Antibiotic Therapy Did Not Prevent the Rupture of Mycotic Aneurysm of the Superior Mesenteric Artery

The Heart Surgery Forum ◽

10.1532/hsf.1322 ◽

2015 ◽

Vol 18 (3) ◽

pp. 088

Author(s):

Ye-tao Li ◽

Xiao-bin Liu ◽

Tao Wang

Keyword(s):

Abdominal Pain ◽

Infective Endocarditis ◽

Aortic Valve ◽

Superior Mesenteric Artery ◽

Mesenteric Artery ◽

Mycotic Aneurysm ◽

Acute Abdominal Pain ◽

Rare Complication ◽

Emergency Operation ◽

History Of

<p class="p1"><span class="s1">Mycotic aneurysm of the superior mesenteric artery (SMA) is a rare complication of infective endocarditis. We report a case with infective endocarditis involving the aortic valve complicated by multiple septic embolisms. The patient was treated with antibiotics for 6 weeks. During preparation for surgical treatment, the patient developed acute abdominal pain and was diagnosed with a ruptured SMA aneurysm, which was successfully treated with an emergency operation of aneurysm ligation. The aortic valve was replaced 17 days later and the patient recovered uneventfully. In conclusion, we present a rare case with infective endocarditis (IE) complicated by SMA aneurysm. Antibiotic treatment did not prevent the rupture of SMA aneurysm. Abdominal pain in a patient with a recent history of IE should be excluded with ruptured aneurysm.</span></p>

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