Clinical judgment to estimate pretest probability in the diagnosis of Cushing's syndrome under a Bayesian perspective

Abstract

Objective: To estimate the pretest probability of Cushing's syndrome (CS) diagnosis by a Bayesian approach using intuitive clinical judgment. Materials and methods: Physicians were requested, in seven endocrinology meetings, to answer three questions: "Based on your personal expertise, after obtaining clinical history and physical examination, without using laboratorial tests, what is your probability of diagnosing Cushing's Syndrome?"; "For how long have you been practicing Endocrinology?"; and "Where do you work?" . A Bayesian beta regression, using the WinBugs software was employed. Results: We obtained 294 questionnaires. The mean pretest probability of CS diagnosis was 51.6% (95%CI: 48.7-54.3). The probability was directly related to experience in endocrinology, but not with the place of work. Conclusion: Pretest probability of CS diagnosis was estimated using a Bayesian methodology. Although pretest likelihood can be context-dependent, experience based on years of practice may help the practitioner to diagnosis CS. Arq Bras Endocrinol Metab. 2012;56(9):633-7 Keywords Cushing's syndrome; Bayes theorem; pretest probability RESUMO Objetivo: Estimar a probabilidade pré-teste do diagnóstico de síndrome de Cushing (SC) por meio de julgamento clínico utilizando abordagem Bayesiana. Materiais e métodos: Médicos responderam a três perguntas, em sete congressos de endocrinologia. Após obtenção da história clínica/exame físico, sem exames laboratoriais, apenas com base em sua experiência pessoal, qual a probabilidade de diagnosticar SC?; Há quanto tempo você pratica endocrinologia?; Onde você trabalha? Uma regressão beta Bayesiana, utilizando o software WinBugs, foi empregada. Resultados: Foram obtidos 294 questionários. A estimativa Bayesiana da probabilidade média de diagnosticar SC foi 51,6% (IC 95%: 48,3). Houve relação direta entre probabilidade de diagnosticar SC e experiência da prática endócrina, porém não com o local de trabalho. Conclusão: A probabilidade pré-teste do diagnóstico de SC foi estimada utilizando uma metodologia Bayesiana. Embora a probabilidade pré-teste possa ser dependente do contexto, a experiência de anos de prática pode auxiliar no diagnóstico intuitivo da CS. Arq Bras Endocrinol Metab. 2012;56(9):633-7 Descritores Síndrome de Cushing; teorema de Bayes; probabilidade pré-teste

From first symptoms to final diagnosis of Cushing's disease: experiences of 176 patients

“…This underlines the importance of the endocrinologist who is familiar with the clinical features of the disease. In our study, the diagnosis of CD was made in 69.9% of cases by an endocrinologist and even attendants of endocrinology meetings rated their ability to clinically diagnose CS as dependent on their years of clinical practice (14).…”

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Development and internal validation of a prediction tool to aid the diagnosis of Cushing's syndrome in dogs attending primary‐care practice

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Constructing diagnostic likelihood: clinical decisions using subjective versus statistical probability

“…Their prediction of the presence of a disease improves with clinical experience,18 but it is not clear whether this is matched by an improved understanding of probability.…”