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Cost-Effectiveness of Digital Subtraction Angiography in the Setting of Computed Tomographic Angiography Negative Subarachnoid Hemorrhage

Jethwa, Pinakin R. MD*; Punia, Vineet MD; Patel, Tapan D. BS*; Duffis, E. Jesus MD*,‡; Gandhi, Chirag D. MD*,§; Prestigiacomo, Charles J. MD, FACS*,‡,§

doi: 10.1227/NEU.0b013e318282a578
Research-Human-Clinical Studies

BACKGROUND: Recent studies have documented the high sensitivity of computed tomography angiography (CTA) in detecting a ruptured aneurysm in the presence of acute subarachnoid hemorrhage (SAH). The practice of digital subtraction angiography (DSA) when CTA does not reveal an aneurysm has thus been called into question.

OBJECTIVE: We examined this dilemma from a cost-effectiveness perspective by using current decision analysis techniques.

METHODS: A decision tree was created with the use of TreeAge Pro Suite 2012; in 1 arm, a CTA-negative SAH was followed up with DSA; in the other arm, patients were observed without further imaging. Based on literature review, costs and utilities were assigned to each potential outcome. Base-case and sensitivity analyses were performed to determine the cost-effectiveness of each strategy. A Monte Carlo simulation was then conducted by sampling each variable over a plausible distribution to evaluate the robustness of the model.

RESULTS: With the use of a negative predictive value of 95.7% for CTA, observation was found to be the most cost-effective strategy ($6737/Quality Adjusted Life Year [QALY] vs $8460/QALY) in the base-case analysis. One-way sensitivity analysis demonstrated that DSA became the more cost-effective option if the negative predictive value of CTA fell below 93.72%. The Monte Carlo simulation produced an incremental cost-effectiveness ratio of $83 083/QALY. At the conventional willingness-to-pay threshold of $50 000/QALY, observation was the more cost-effective strategy in 83.6% of simulations.

CONCLUSION: The decision to perform a DSA in CTA-negative SAH depends strongly on the sensitivity of CTA, and therefore must be evaluated at each center treating these types of patients. Given the high sensitivity of CTA reported in the current literature, performing DSA on all patients with CTA negative SAH may not be cost-effective at every institution.

ABBREVIATIONS: CTA, computed tomography angiography

DSA, digital subtraction angiography

mRS, modified Rankin scores

NASAH, nonaneurysmal subarachnoid hemorrhage

NPV, negative predictive value

SAH, subarachnoid hemorrhage

*Department of Neurological Surgery, UMDNJ – New Jersey Medical School, Newark, New Jersey

Department of Neurology and Neuroscience, UMDNJ – New Jersey Medical School, Newark, New Jersey

§Department of Radiology, UMDNJ – New Jersey Medical School, Newark, New Jersey

Correspondence: Pinakin R. Jethwa, MD, New Jersey Medical School, Department of Neurological Surgery, 90 Bergen St, Suite 8100, Newark, NJ 07103. E-mail: pinakin.jethwa.md@gmail.com

Received August 22, 2012

Accepted October 27, 2012

Copyright © by the Congress of Neurological Surgeons