Cost-effectiveness of CTA, MRA and DSA in patients with non-traumatic subarachnoid haemorrhage

OBJECTIVES Intra-arterial digital subtraction angiography (DSA), magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) are imaging modalities used for diagnostic work-up of non-traumatic subarachnoid haemorrhage. The aim of our study was to compare the cost-effectiveness of MRA, DSA and CTA in the first year after the bleed. METHODS A decision model was used to calculate costs and benefits (in quality-adjusted life-years [QALYs]) that accrued to cohorts of 1,000 patients. Costs and characteristics of diagnostic tests, therapy, patients' quality of life and associated costs were respected. The diagnostic strategy with highest QALYs and lowest costs was considered most cost-effective. RESULTS DSA was the most effective diagnostic option, yielding on average 0.6039 QALYs (95 % CI, 0.5761-0.6327) per patient, followed by CTA 0.5983 QALYs (95 % CI, 0.5704-0.6278) and MRA 0.5947 QALYs (95 % CI, 0.5674-0.6237). Cost was lowest for DSA (39,808 ; 95 % CI, 37,182-42,663), followed by CTA (40,748 ; 95 % CI, 37,937-43,831) and MRA (41,814 ; 95 % CI, 38,730-45,146). A strategy of CTA followed by DSA if CTA was negative or coiling deemed not feasible, was as effective as DSA alone at average costs of 39,767 (95 % CI, 36,903-42,402). CONCLUSION A combined strategy of CTA and DSA was found to be the most cost-effective diagnostic approach. MAIN MESSAGES • We defined a standard model for cost-effectiveness analysis in diagnostic imaging. • Comparing total 1-year health costs and benefits, CTA is superior to MRA. • A strategy of combining CTA and DSA was found to be the most cost-effective diagnostic approach.