Diagnostic test evaluations are susceptible to random and systematic error. Simulated non-differential random error for six different error distributions was evaluated for its effect on measures of diagnostic accuracy for a brucellosis competitive ELISA. Test results were divided into four categories: < 0.25, 0.25-0.349, 0.35-0.499, and > or = 0.50 proportions inhibition for calculation of like...

BACKGROUND Infective endocarditis (IE) is a diagnostic challenge. We aimed to systemically summarize the current evidence on the diagnostic value of procalcitonin (PCT) in identifying IE. METHODS We searched EMBASE, MEDLINE, Cochrane database, and reference lists of relevant articles with no language restrictions through September 2012 and selected studies that reported the diagnostic perform...

OBJECTIVES To assess the likelihood ratios of diagnostic strategies for pulmonary embolism and to determine their clinical application according to pretest probability. DATA SOURCES Medline, Embase, and Pascal Biomed and manual search for articles published from January 1990 to September 2003. STUDY SELECTION Studies that evaluated diagnostic tests for confirmation or exclusion of pulmonary...

BACKGROUND Likelihood ratios offer important advantages over sensitivity and specificity for characterizing diagnostic tests. They can capture the magnitude of abnormality of test results, whereas sensitivity and specificity require that the test results be dichotomized into positive or negative. This is an important advantage because many diagnostic tests are measured on continuous or ordinal ...

PURPOSE To assess the consequences of lossy compression on the diagnostic accuracy of CT colonography for detecting colonic polyps. MATERIALS AND METHODS Helical CT images of cleansed colonic segments were evaluated. Source images were compressed to 1:1, 10:1, and 20:1 ratios with lossy wavelet compression. Two independent readers blinded to corresponding colonoscopic results analyzed 144 ran...

INTRODUCTION Medical diagnostic tests are evaluated based on measures of sensitivity (Sn), specificity (Sp), and likelihood ratios (LR). These procedures are limited in the event of a biased gold standard or missing data. Interpretations of these measures are frequently inappropriate. PURPOSE The Rasch measurement model (RMM) was examined as a method to provide evidence of diagnostic test uti...

background although magnetic resonance spectroscopy (mrs) has been shown as an effective diagnostic tool in distinguishing inflammation from neoplasm in cystic brain lesions, the optimum approach in selecting the portions of lesions in mrs and the possible effects of different times of echoes (tes) remains unknown. objectives to determine the most effective te in diagnosing neoplastic lesions b...