Stress PET showed the lowest cost per effect or utility in patients with a pretest likelihood of CAD <0.70, whereas coronary angiography was most cost-effective for those with a likelihood >0.70.
What is the most cost-effective diagnostic algorithm (ExECG, SPECT, PET, or angiography) for diagnosing obstructive CAD based on pretest probability?
The optimal cost-effective diagnostic strategy for CAD depends on pretest probability, favoring stress PET for probability < 0.70 and direct angiography for probability > 0.70.
BACKGROUND: To compare cost-effectiveness and utility of four clinical algorithms to diagnose obstructive coronary atherosclerotic heart disease (CAD), we compared exercise ECG (ExECG), stress single photon emission computed tomography (SPECT), positron emission tomography (PET), and coronary angiography. METHODS AND RESULTS: Published data and a straightforward mathematical model based on Bayes' theorem were used to compare strategies. Effectiveness was defined as the number of patients with diagnosed CAD, and utility was defined as the clinical outcome, ie, the number of quality-adjusted life years (QALY) extended by therapy after the diagnosis of CAD. Our model used published values for costs, accuracy, and complication rates of tests. Analysis of the model indicates the following results. (1) The direct cost (fee) for each test differs considerably from total cost per delta QALY. (2) As pretest likelihood of CAD (pCAD) in the population increases, there is a linear increase in cost per patient tested but a hyperbolic decrease in cost per effect and cost per utility unit, ie, increased cost-effectiveness and decreased cost per utility unit. (3) At pCAD 0.70.
Patterson et al. (Sun,) conducted a other in obstructive coronary atherosclerotic heart disease (CAD). Stress PET, SPECT, ExECG, and coronary angiography was evaluated on Cost-effectiveness (number of patients with diagnosed CAD) and utility (QALY extended by therapy). Stress PET showed the lowest cost per effect or utility in patients with a pretest likelihood of CAD <0.70, whereas coronary angiography was most cost-effective for those with a likelihood >0.70.