Wells score and Pulmonary Embolism Rule Out Criteria in preventing over investigation of pulmonary embolism in emergency departments.

Abstract

Unnecessary diagnostic tests are usually ordered to most of the patients with dyspnea or pleuritic chest pain, because of the worse outcomes of missed diagnosis of pulmonary embolism (PE). To identify rates and causes of over investigation for PE and to search whether it was possible to reduce this over investigation by using Wells score and Pulmonary Embolism Rule Out Criteria (PERC). A retrospective observational cohort study performed in an emergency department of a tertiary care university hospital. All patients who were ordered diagnostic with the suspicion of PE were included in the study. They were grouped into two as PE (+) and PE (-) and compared. Among 108 patients, 53 (49%) were diagnosed as PE (+) and overdiagnosis was present in 55 (51%) patients i.e., PE (-). The sensitivity of high Wells score was 43%, specificity 78%, positive predictive value 66% and negative predictive value 59%. PERC criteria found to be negative (when all of the eight criteria were fulfilled) in only five patients. The sensitivity of the test was 98%, specificity 7%, positive predictive value 50%, negative predictive value 80%. When individual parameters of PERC were evaluated solely for the exclusion of PE; "no leg swelling" and "no previous deep venous thrombosis or PE history" were found significantly negatively correlated with PE diagnosis (p= 0.001, r= -0.325 and p= 0.013, r= -0.214 respectively). Over investigation of PE in emergency departments still remains as an important problem. In order to prevent this, the clinical prediction rules must be developed further and their use in combination should be searched in future studies.