Analysis of the Appropriateness of Pharmacogenetic Test Ordering at Samutsakhon Hospital
Keywords:
Pharmacogenomics, HLA-B, Test ordering appropriateness, Financial lossAbstract
Background: Pharmacogenomics utilizes genetic information to guide individualized drug selection and dosing. Samutsakhon Hospital has provided pharmacogenetic testing for HLA-B*15:02, HLA-B*58:01, HLA-B*57:01, and NAT2 since 2015. Despite an existing alert system within the hospital information system, inappropriate test ordering has been observed; however, no systematic study has analyzed this issue.
Objective: To analyze the inappropriateness of pharmacogenetic test ordering, including duplicate testing, incorrect gene testing, and negative genetic test results without subsequent drug prescription, and to assess the associated financial loss.
Methods: A retrospective descriptive study was conducted using data from the HOSxP database. All inpatients and outpatients who underwent HLA-B*15:02, HLA-B*58:01, HLA-B*57:01, and NAT2 testing at Samutsakhon Hospital from fiscal year 2015 to 2024 were included. Data were analyzed using descriptive statistics including frequency and percentage.
Results: A total of 1,081 cases of inappropriate test ordering were identified, comprising duplicate testing (140 cases, 12.95%), incorrect gene testing (13 cases, 1.20%), and negative genetic test results without subsequent drug prescription (928 cases, 85.85%). The total financial loss amounted to 2,271,000 Thai Baht, with tests ordered without drug prescription accounting for the largest proportion at 1,941,250 Baht.
Conclusion: The availability of pharmacogenetic testing services and alert systems alone is insufficient to ensure appropriate utilization. Hospitals should develop a comprehensive clinical decision support system for pharmacogenomics, with pharmacists playing a key role in screening test appropriateness, interpreting results, and monitoring the clinical application of test outcomes.
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