Understanding the Barriers and Enablers of Pharmacogenetics Testing in Primary Care in Singapore: A Qualitative Study

Pharmacogenetic testing promises safer, personalized prescribing, yet its adoption in primary care in Singapore remains limited and underexplored. The aim of this study was to, 1) examine perceptions, attitudes, and beliefs about pharmacogenetic testing among primary care physicians (PCPs) and patients in Singapore, and 2) to compare acceptability between those who did and did not participate in a prior pharmacogenetic feasibility study. We conducted one-to-one semi-structured interviews with a purposive sample of 10 PCPs (6 had joined an earlier feasibility study) and 15 patients (7 previously tested with pharmacogenetic testing). Interviews (mean=35 minutes) were audio-recorded, transcribed verbatim, and analysed thematically by three investigators. Ethical approval was obtained (IRB2019-07-035). Five principal themes emerged: 1) Perceptions of acceptability and test accuracy--broad support for pharmacogenetics to reduce trial-and-error prescribing but persistent concerns about result reliability and medico-legal risk; 2) Appropriate financial context--cost sensitivity in Singapore with expectations for government subsidies and incentives for PCPs; 3) Physician education and communication--variable pharmacogenetic expertise, perceived inadequacy of training, need for expert support, and challenges explaining probabilistic results to patients; 4) Integration into clinical records--frustration with standalone pharmacogenetic software and a desire for EMR integration; 5) Data privacy and insurance implications--concerns about insurer access and potential premium and eligibility impacts. No significant attitude differences were observed between participating and non-participating PCPs. Patients and PCPs generally favor pharmacogenetic testing in primary care but identify actionable barriers, cost, training, and data integration and safeguards, that must be addressed to support implementation in Singapore.