Our objective was to evaluate the diagnostic value of computed tomography angiography (CTA) and ventilation perfusion (V/Q) scan in the assessment of pulmonary embolism (PE) by means of a Bayesian statistical model. Wells criteria defined pretest probability. Sensitivity and specificity of CTA and V/Q scan for PE were derived from pooled meta-analysis data. Likelihood ratios calculated for CTA and V/Q were inserted in the nomogram. Absolute (ADG) and relative diagnostic gains (RDG) were analyzed comparing post- and pretest probability. Comparative gain difference was calculated for CTA ADG over V/Q scan integrating ANOVA p value set at 0.05. The sensitivity for CT was 86.0% (95% CI: 80.2%, 92.1%) and specificity of 93.7% (95% CI: 91.1%, 96.3%). The V/Q scan yielded a sensitivity of 96% (95% CI: 95%, 97%) and a specificity of 97% (95% CI: 96%, 98%). Bayes nomogram results for CTA were low risk and yielded a posttest probability of 71.1%, an ADG of 56.1%, and an RDG of 374%, moderate-risk posttest probability was 85.1%, an ADG of 56.1%, and an RDG of 193.4%, and high-risk posttest probability was 95.2%, an ADG of 36.2%, and an RDG of 61.35%. The comparative gain difference for low-risk population was 46.1%; in moderate-risk 41.6%; and in high-risk a 22.1% superiority. ANOVA analysis for LR+ and LR- showed no significant difference (p = 0.8745, p = 0.9841 respectively). This Bayesian model demonstrated a superiority of CTA when compared to V/Q scan for the diagnosis of pulmonary embolism. Low-risk patients are recognized to have a superior overall comparative gain favoring CTA.
Our objective was to evaluate the diagnostic value of computed tomography angiography ( CTA ) and ventilation perfusion ( V / Q ) scan in the assessment of pulmonary embolism ( PE ) by means of a Bayesian statistical model . Wells criteria defined pretest probability . Sensitivity and specificity of CTA and V / Q scan for PE were derived from pooled meta - analysis data . Likelihood ratios calculated for CTA and V / Q were inserted in the nomogram . Absolute ( ADG ) and relative diagnostic gains ( RDG ) were analyzed comparing post- and pretest probability . Comparative gain difference was calculated for CTA ADG over V / Q scan integrating ANOVA p value set at 0.05 . The sensitivity for CT was 86.0 % ( 95 % CI : 80.2 % , 92.1 % ) and specificity of 93.7 % ( 95 % CI : 91.1 % , 96.3 % ) . The V / Q scan yielded a sensitivity of 96 % ( 95 % CI : 95 % , 97 % ) and a specificity of 97 % ( 95 % CI : 96 % , 98 % ) . Bayes nomogram results for CTA were low risk and yielded a posttest probability of 71.1 % , an ADG of 56.1 % , and an RDG of 374 % , moderate - risk posttest probability was 85.1 % , an ADG of 56.1 % , and an RDG of 193.4 % , and high - risk posttest probability was 95.2 % , an ADG of 36.2 % , and an RDG of 61.35 % . The comparative gain difference for low - risk population was 46.1 % ; in moderate - risk 41.6 % ; and in high - risk a 22.1 % superiority . ANOVA analysis for LR+ and LR- showed no significant difference ( p = 0.8745 , p = 0.9841 respectively ) . This Bayesian model demonstrated a superiority of CTA when compared to V / Q scan for the diagnosis of pulmonary embolism . Low - risk patients are recognized to have a superior overall comparative gain favoring CTA .
What can be predicted with the Wells criteria?
What can be predicted with the Wells criteria ?
pulmonary embolism
pulmonary embolism