Combined results of HLA testing and prescription records
We investigated the status of the eight ADR-related HLA-alleles, seven risk drugs, and target ADRs reported in 11,988 HLA-tested patients, as shown in Figure 2 . In total, 4,092 patients (34.1%) had at least one of the risk HLA alleles. The HLA-B*58:01 allele had the highest frequency at 11.0% (Figure 2 ). In addition, 4,583 patients (38.2%) were prescribed at least one of the seven risk drugs. The drug with the highest number of prescriptions was allopurinol (n = 2,782, 23.2%).
Some discrepancies in the reports of adverse events were identified using SUPREME® and the ICSR. To resolve the discrepancies, we regarded all cases of the reported drug-related side effects in either of the two databases (SUPREME® and ICSR) as true. Additionally, when the severity of ADRs reported in the two databases did not match, we assumed that more severe events took place. Data of a total of 580 patients with ADRs related to the seven PGx drugs were evaluated.