Objectives: Application of the theorem of Bayes for the study of the usefulness of complementary quantitative and qualitative assessment of the effectiveness of ultrasound diagnosis in order to provide the clinician with a tool to accurately assess the effectiveness of these tests in diagnosing abdominal pain appendix subject box.
Methods: Retrospective cohort of 184 patients treated from January 2009 to June 2010 for abdominal pain suggestive of acute abdomen, of which 145 were operated. Were established as predictors of appendiceal disease abdominal exploration, ultrasonography and plasma levels of CRP and leukocytes. The statistical methodology developed by the systematic Bayesian prior determination of ROC curve and calculation of odds and post-test probability as pretest probability based on physical examination.
Results: The ROC analysis cut-points set of quantitative tests on the values of WBC >12,800 and CRP >1.8 mg/dl. Applying the model to the white cell count increased clinical certainty of this test in 11.3 points and 13.9 PCR. The combined use of both the index rose 32 points. The effectiveness of ultrasound method showed a statistically significant 94% and an increase in diagnostic certainty of 48 points.
Discussion: It is recommended to base the development of protocols and clinical guidelines in practice of test ultrasound as first, and joint determination of inflammatory markers, when that was questionable or negative. Further studies are proposed to increase the clinical certainty to reduce laparotomy white and diagnostic delays in this condition.