Value of a Hypothetical Pharmacogenomic Test for the Diagnosis of Statin-Induced Myopathy in Patients at High Cardiovascular Risk

Abstract

We recently conducted two economic evaluations of a hypothetical pharmacogenomic test for statin-induced myopathy (SIM) in patients at high cardiovascular risk. Although the models differed in modeling technique and data inputs, both yielded similar results. We believe our approach to assessing the economic value of a diagnostic test was highly advantageous as it characterized the complete range of false-negative and false-positive test outcomes. We used a broad interpretation of test parameters that reflected physician and patient behavioral responses to the test results and accounted for patient adherence to treatment. Both economic evaluations indicated that a highly accurate pharmacogenomic test for SIM would provide a positive incremental net monetary benefit (INMB) for a provincial payer in Canada. However, the value of the test would depend on its ability to accurately diagnose patients when they experience musculoskeletal pain symptoms and guide patients with a test result indicating no SIM to adhere to treatment. Interestingly, our results indicated that a highly inaccurate test would still yield a positive INMB. We found this surprising result was driven by the imbalance of the risk of cardiovascular events outweighing the risk of rhabdomyolysis in patients at high cardiovascular risk. A highly accurate pharmacogenomic test for SIM in patients at high cardiovascular risk would provide economic value for payers. However, the economic and clinical value of the test would depend on the credibility of the test results and their success in influencing patients without SIM to adhere to therapy.