The diagnostic yield of three clinical prediction rules for pulmonary embolism

Abstract

Objective: pulmonary embolism (PE) is the third cause of cardiovascular death worldwide. The evaluation of pre-test probability using the Wells, Geneva and Pisa clinical prediction rules has been amply validated in prior studies. However, there are insufficient data for evaluating their diagnostic yield in a Colombian population. The goal of this article is to evaluate the yield of these scales in our population.
Methods: this was a retrospective cohort study with diagnostic test analysis in a tertiary level hospital from 2009 to 2017, which included all subjects over the age of 18 who had undergone a chest computed tomography angiography (CTA) due to a clinical suspicion of PE. All the necessary variables for constructing the Wells, Geneva and Pisa rules were recorded. Each score was calculated numerically and then classified according to probability. Pulmonary embolism was diagnosed through a CTA read by a radiologist. The data were entered on an Excel spreadsheet and analyzed using a licensed SPSS statistical program.
Results: a total of 507 subjects were included for Wells and Geneva scores and 339 for the Pisa score. The average age was 56 years (SD: 19.8) and 56.6% were males. A statistically significant relationship was found between the different calculated scores and the diagnosis of pulmonary embolism: low, intermediate and high Wells probability p<0.001; less probable and probable Wells p<0.001; low, intermediate and high Geneva p=0.006; and low, intermediate, moderate and high Pisa p=0.001. The ACOR for Wells was 0.715 (95% CI:0.663-0.767) (p<0.001), for Geneva was 0.611 (95% CI:0.553-0.668) (p<0.001), and for Pisa was 0.643 (95% CI:0.574-0.713) (p<0.001).
Conclusions: the study showed a greater PE diagnostic yield using the Wells score in our setting. There are limitations to the application and development of the Pisa score asociated with a lower yield in our patients