Use of YEARS Algorithm in Military Health Care Beneficiaries to Evaluate Use of Computed Tomography Pulmonary...

Pulmonary embolism (PE) can be difficult to rule out without computed tomography pulmonary angiograms (CTPAs), as presentations vary. Multiple clinical decision rules (CDRs) exist to risk-stratify patients to avoid unnecessary CTPAs. However, the currently used CDRs are complex, and research has shown low compliance with their usage. The YEARS algorithm is less complex and excludes patients from CTPA if PE is not the most likely diagnosis, they do not have a history of hemoptysis, and no clinical signs of deep vein thrombosis, is less complex. However, no studies have evaluated YEARS in the U.S. Military health care beneficiary population. Therefore, this study sought to determine if implementing the YEARS algorithm could decrease the number of CTPAs ordered to rule out PE in low-risk patients.

This retrospective, single-center cohort study applied the YEARS algorithm to low-risk military beneficiaries presenting to the emergency department in the calendar year 2020 at a single U.S. Army MTF. The primary outcome was the number of CTPAs indicated by the YEARS algorithm versus the number ordered via standard practice. We used chi-square testing to compare the number of subjects in whom YEARS indicated CTPA (meets criteria/does not meet criteria) versus the actual number of subjects who underwent CTPA (meets criteria/does not meet criteria). The secondary outcomes included applying YEARS similarly to the number of subjects >50 years of age (as opposed to age-adjusted d-dimer), determining the number of pregnant patients who could have avoided CTPA via application of YEARS, and assessing possible cost savings via reduction of CTPA.

We included 353 subjects during the study period, 271 of whom underwent CTPA. YEARS would have only indicated 25 of them, P = .018. In patients >50 years of age, 164 underwent CTPA versus nine who met YEARS criteria, P = .014. Among pregnant patients, six underwent CTPA versus one who YEARS would have indicated, P = .130. Application of the YEARS algorithm would have led to a 90.8% reduction in CTPAs ordered with an overall known missed PE rate of 1.1%. Applying the YEARS algorithm in 2020 could have led to 246 fewer CTPAs at a minimum cost savings of $38,762.22 for the MTF based on the coded billing cost of $157.57 per CTPA when local staff radiologists performed image interpretation. This estimate does not consider the additional undisclosed cost of contracted radiologists interpreting after regular duty hours.

For our military beneficiaries, our study indicates that the YEARS algorithm would have reduced CTPA utilization in all age ranges and potentially among pregnant patients with a known missed PE rate of 1.1%.