[Diagnostic performance of immunologic tests in amebic liver abscess using receiver operating characteristic curves]. / Rendimiento diagnóstico de las pruebas inmunológicas en absceso hepático amibiano a través de curvas de características operantes del receptor.

Objectives. 1) To identify the tests of immunological diagnosis with a high diagnostic efficiency in amebic liver abscess. 2) To determine the ideal cutoff point for such tests. 3) To identify the influence degree of the antigen used over the test efficiency. Design. Comparative survey. Study units. Analysis of 24 articles identified in the medical literature about tests of immunological diagnosis in amebic liver abscess. Measurements. Starting from the articles, operating characteristics curves (ROC) were established derived from the test application to patients with amebic liver abscess. Results. A great variability in the diagnostic efficiency was identified between the various tests, even when the analysis was focused on the investigations of a specific test. It was not possible to conclude which test had a major degree of efficiency due to such variability. The cutoff level considered as relevant was higher than the one traditionally used for indirect hemagglutination and it had concordance with the one presently accepted for the fluorescence antibodies test. By maintaining steady the spectrum of the study patients and the type of test, variability among the tests persisted. This was due to the use of different antigens. Conclusions. A great variation in the diagnostic efficiency of the analyzed tests was identified. The variation source was the type of test, the antigen used and probably the illness spectrum.

[Evaluation of immunologic diagnostic tests in amebiasis: diagnosis or bias? A critical review of the literature]. / Evaluación de las pruebas de diagnóstico inmunológico en amibiasis: diagnóstico ó sesgo?

OBJECTIVE: 1. To describe the frequency of adherence to methodologic criteria proposed for assessment of diagnostic tests. 2. To identify potential bias. 3. To construct Receiver Operating Characteristic (ROC) curves based on data published on the assessed papers. DESIGN: Descriptive cross-sectional survey. STUDY MATERIAL: All papers listed under diagnosis and immunological headings of amebiasis in the Index Medicus from 1970 to 1988. STUDY UNITS: 80 papers. MEASUREMENT: a: Adherence to methodologic criteria proposed for assessment of diagnostic test. b: presence of potential bias. MAIN RESULTS: The adherence to methodologic criteria varied 1 to 55% of the papers. The comparison with a "gold standard" occurred in 40% the independent "blind" assessment occurred in 6% the setting for the study was described 1%. The study of an appropriate spectrum of disease was done in 11%. We were able to construct ROC curves with data from 37 papers and differences were observed among studies evaluating the same test. A high proportion of papers had potential bias. CONCLUSIONS: The adherence to methodologic standards is poor in the papers analyzed in this series. Consequently the frequency of potential bias was high.