DSCT more cost-effective than invasive angiography in intermediate-risk populations
MedWire News: Dual-source computed tomography (DSCT) is more cost-effective than invasive coronary angiography for diagnosing coronary artery disease (CAD) in patients with an intermediate pretest disease risk, researchers estimate.
However, this is only the case in patient cohorts with a CAD prevalence below a threshold of 55%, write Marc Dorenkamp (Charité-Universitätsmedizin, Berlin, Germany) and co-authors in the journal Heart.
They investigated the direct costs and cost-effectiveness of DSCT in comparison with invasive coronary angiography in 90 consecutive patients with an intermediate pretest likelihood of CAD.
The authors based their cost calculations on a detailed analysis of direct costs, and applied generally accepted accounting principles. They then used a mathematical model based on Bayes' theorem to compare the cost-effectiveness of invasive coronary angiography and DSCT.
Total cost included direct cost, induced cost, and cost of complications. Effectiveness was defined as the ability of a diagnostic test to identify a patient with CAD.
The findings revealed that the direct cost of DSCT was lower than that of coronary angiography, at US$141.74 (€98.60) versus US$456.79 (€317.75).
Model calculations indicated that cost-effectiveness would grow hyperbolically with increasing prevalence of CAD, the authors report.
As the prevalence of CAD in the study cohort was 24%, DSCT was more cost-effective, at US$1394.19 (€970) for each patient correctly diagnosed as having CAD, than coronary angiography, which cost US$1946.12 (€1354) for each patient.
But in a hypothetical cohort with a CAD prevalence of 49%, DSCT and invasive angiography were equally effective, with costs of US$910.02 (€633).
At a higher disease prevalence, invasive coronary angiography became more cost-effective, the researchers explain.
Specifically, they found that above a disease prevalence threshold of 55%, proceeding directly to invasive coronary angiography was more cost-effective than DSCT.
As an intermediate pretest likelihood generally ranges from 20% to 80%, Dorenkamp and team explain that "carefully performed DSCT coronary angiography may be an economically efficient alternative to invasive angiography."
They conclude: "The most important step for physicians in selecting the appropriate diagnostic approach is based on a clinical estimation of disease likelihood."
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By Piriya Mahendra