Cost-Effectiveness of Panel Tests for Multiple Pharmacogenes Associated With Adverse Drug Reactions: An Evaluation Framework.

The cost-effectiveness of testing for multiple genes implicated in adverse drug reactions requires the simultaneous assessment of all actionable information, including future prescribing decisions based on incidental findings. We developed methodology for determining the value of pharmacogenetic panel tests, illustrated with a multigene panel, including HLA-A*31:01, HLA-B*15:02, HLA-B*57:01, HLA-B*58:01, HLA-B (158T), and HLA-DQB1 (126Q). If the findings for all alleles are acted upon, regardless of their individual cost-effectiveness, the HLA panel resulted in cost savings of £378 (US $491), and a quality-adjusted life year gain of 0.0069. Based on a stratified analysis and compared with no testing, initial use of the panel was cost-effective in patients eligible for abacavir (HLA-B*57:01), carbamazepine (HLA-A*31:01), and clozapine (HLA-B (158T) and HLA-DQB1 (126Q)), but not for carbamazepine (HLA-B*15:02) or allopurinol (HLA-B*58:01). The methods presented allow for the assessment of the cost-effectiveness of multiple-gene panels.

Cost-effectiveness of screening for HLA-A*31:01 prior to initiation of carbamazepine in epilepsy.

OBJECTIVE: Carbamazepine causes severe cutaneous adverse drug reactions that may be predicted by the presence of the HLA-A*31:01 allele in northern European populations. There is uncertainty as to whether routine testing of patients with epilepsy is cost-effective. We conducted an economic evaluation of HLA-A*31:01 testing from the perspective of the National Health Service (NHS) in the United Kingdom. METHODS: A short-term, decision analytic model was developed to estimate the outcomes and costs associated with a policy of routine testing (with lamotrigine prescribed for patients who test positive) versus the current standard of care, which is carbamazepine prescribed without testing. A Markov model was used to estimate total costs and quality-adjusted life-years (QALYs) over a lifetime to account for differences in drug effectiveness and the long-term consequences of adverse drug reactions. RESULTS: Testing reduced the expected rate of cutaneous adverse drug reactions from 780 to 700 per 10,000 patients. The incremental cost-effectiveness ratio for pharmacogenetic testing versus standard care was £12,808 per QALY gained. The probability of testing being cost-effective at a threshold of £20,000 per QALY was 0.80, but the results were sensitive to estimated remission rates for alternative antiepileptic drugs (AEDs). SIGNIFICANCE: Routine testing for HLA-A*31:01 in order to reduce the incidence of cutaneous adverse drug reactions in patients being prescribed carbamazepine for epilepsy is likely to represent a cost-effective use of health care resources.