Summary
Background: The Pulmonary Embolism (PE) Severity Index identifies emergency department (ED) patients
with acute PE that can be safely managed without hospitalization. However, the Index
comprises 11 weighted variables, complexity that can impede its integration into contextual
work-flow.
Objective: We designed a computerized version of the PE Severity Index (e-Index) to automatically
extract the required variables from discrete fields in the electronic health record
(EHR). We tested the e-Index on the study population to determine its accuracy compared
with a gold standard generated by physician abstraction of the EHR on manual chart
review.
Methods: This retrospective cohort study included adults with objectively-confirmed acute
PE in four community EDs from 2010–2012. Outcomes included performance characteristics
of the e-Index for individual values, the number of cases requiring physician editing,
and the accuracy of the e-Index risk category (low vs. higher).
Results: For the 593 eligible patients, there were 6,523 values automatically extracted. Fifty
one of these needed physician editing, yielding an accuracy at the value-level of
99.2% (95% confidence interval [CI], 99.0%-99.4%). Sensitivity was 96.9% (95% CI,
96.0%-97.9%) and specificity was 99.8% (95% CI, 99.7%-99.9%). The 51 corrected values
were distributed among 47 cases: 43 cases required the correction of one variable
and four cases required the correction of two. At the risk-category level, the e-Index
had an accuracy of 96.8% (95% CI, 95.0%-98.0%), under-classifying 16 higher-risk cases
(2.7%) and over-classifying 3 low-risk cases (0.5%).
Conclusion: Our automated extraction of variables from the EHR for the e-Index demonstrates substantial
accuracy, requiring a minimum of physician editing. This should increase user acceptability
and implementation success of a computerized clinical decision support system built
around the e-Index, and may serve as a model to automate other complex risk stratification
instruments.
Citation: Vinson DR, Morley JE, Huang J, Liu V, Anderson ML, Drenten CE, Radecki RP, Nishijima
DK, Reed ME. The accuracy of an electronic pulmonary embolism severity index auto-populated
from the electronic health record. Appl Clin Inf 2015; 6: 318–333
http://dx.doi.org/10.4338/ACI-2014-12-RA-0116
Keywords
Clinical decision support systems - electronic health record - risk assessment - pulmonary
embolism - emergency medicine - data completeness