The assessment of diagnostic tests

To determine whether improvements have occurred since a survey of the 1982 literature assessing diagnostic tests, the authors evaluated all English-language articles that assessed clinical diagnostic tests in abridged Index Medicus journals in 1985, and that had the terms sensitivity and specificity in the title, abstract, or key words. The 89 articles were assessed against seven methodologic criteria, including use of a well-defined “gold standard,” clearly defined test interpretation, blinding, clear data presentation, correct use of sensitivity and specificity, calculation of predictive values, and consideration of prevalence. In comparisons of 1985 vs. 1982 articles, there were significant improvements in five of the seven criteria. For example, the proportion of articles using a well-defined “gold standard” rose from 68% to 88%. Overall, the frequency of papers demonstrating five or more of the seven criteria increased from 26% to 47%. However, predictive values were discussed in only 54% of the articles without, necessarily, consideration of the influence of prevalence as well. This study raises the concern that while the concepts of sensitivity and specificity are now accepted, predictive values remain less well understood. Although there has been an improvement in the assessment of diagnostic tests in published research, attention to accepted methodologic standards is still needed on the part of researchers, reviewers, and editors. Received from the Department of Health Care and Epidemiology, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. Supported by a National Health Scholar Award to Dr. Schechter from the Department of National Health and Welfare of Canada.     

Hemostatic alterations in inflammatory bowel disease

Twelve patients with acute, untreated inflammatory bowel disease (IBD) were followed prospectively for coagulation and platelet function. With no symptomatic coagulopathy, abnormalities were found in all patients. With acute diseases, elevations of fibrinogen (9/12), factor V (8/12), and factor VIII (6/12) were common. Depressions of antithrombin III levels were also observed acutely (8/12). Abnormalities of platelets were both quantitative and qualitative. Thrombocytosis was present (11/12), and abnormalities in the rate and percent platelet aggregation were seen (9/10). During therapy, factors V and VIII, antithrombin III levels, and the quantitative and qualitative platelet abnormalities returned towards normal in direct correlation with sedimentation rate and clinical disease activity.     

Effect of carbenoxolone sodium on aspirin-induced injury of the rat gastric mucosa

Investigations were performed in the rat to examine the effect of carbenoxolone sodium on aspirin-induced gastric mucosal injury. Mucosal damage was quantitated histologically in the body of the stomach (corpus) after a single dose of aspirin and after 2 weeks of daily aspirin. Over dosage ranges of 2–30 mg/kg/day of carbenoxolone and 10–120 mg/kg of aspirin, carbenoxolone treatment conferred no protection, despite evidence of a significant carbenoxolone effect on gastric mucus. This contrasts with the known protective action of carbenoxolone against injury by restraint stress and by corticosteroids. Much current evidence suggests that the mechanisms of erosion production by aspirin differ from those by restraint stress and corticosteroids, and it is likely that the present findings reflect such differences in pathogenesis.     

A Comparison of the Antemortem Clinical Diagnosis and Autopsy Findings for Patients Who Die in the Emergency Department

OBJECTIVES: In spite of advances in medical technology, there remains a high discrepancy rate between the antemortem clinical diagnosis and postmortem examination diagnosis for patients who die in hospitals. The aim of this study was to compare the clinical and postmortem examination diagnoses of patients who died in the emergency department (ED) of a tertiary hospital, and to analyze any discrepancy between them. METHODS: The study was a retrospective chart review of patients who died in the ED of a tertiary referral teaching hospital and a comparison of the antemortem diagnosis with the autopsy diagnosis. Any missed diagnosis was classified, according to the Goldman criteria, into major and minor missed diagnoses. RESULTS: A total of 59 patients were eligible for inclusion in the study. There was complete agreement between the antemortem diagnosis and the autopsy result in 51% of cases. The incidence of major missed diagnoses-where if the diagnosis had been known before the patient died, treatment may have been altered or survival may have been prolonged-was 7%. CONCLUSIONS: There is a significant discrepancy rate between the antemortem diagnosis and the autopsy diagnosis. However, in this study, serious missed diagnoses in which outcome may have been significantly altered are unusual among those who die in the ED of a tertiary referral hospital.