RESUMO
AIM: To evaluate the effect of implementing the Wells score clinical prediction tool (CPT) on rationalising the use of computed tomography pulmonary angiography (CTPA) for diagnosing pulmonary embolism (PE). METHODS: Within a tertiary teaching hospital, a retrospective study was conducted applying Wells score to all CTPA ordered in the first quarter of 2007. Subsequently, an algorithm including Wells score and d-dimer assay was developed to assist clinicians in rationalising their ordering of CTPA. A prospective study was performed from February to August 2009 to assess the impact of this algorithm. CTPA results, d-dimer levels, referral sources and dates were recorded. The number of CTPA performed over a 7-month period following implementation of the algorithm was compared with the same period during the previous year. PE prevalence within each risk category was compared with the published literature. RESULTS: Three hundred and thirty-three patients were investigated with CTPA in the prospective study period. Two hundred and sixty-eight patients (80.4% of cases) had complete data. The prevalence of PE in the present study was 13.8% with 57 (21.2%) patients stratified to low risk, 169 (63.0%) to intermediate risk and 42 (15.6%) to high risk. Subgroup prevalence was 8.8%, 11.8% and 23.8% respectively. Compared with the same period in 2008, 121 (26.6%) less CTPA were performed. CONCLUSION: Institutional implementation of a clinical prediction tool into the decision-making process is feasible and significantly reduces the number of CTPA being performed, with substantial cost savings and patient benefits.
