2.2 Study population and procedures
An overview of the study procedures is presented in Figure 1 .
We included all subjects who underwent PGx testing with a 16-gene PGx
panel between June 2018 and June 2020 through clinical pharmacology
services at two Swiss tertiary care hospitals and associated outpatient
clinics. The reason for PGx testing was either a specific drug-gene pair
relating to current or planned pharmacotherapy, or a request for
preemptive PGx screening. For all subjects the indication for PGx
testing was first evaluated by a senior clinical pharmacologist (SR),
including a consultation and review of all medical diagnoses and
pharmacotherapy. If the indication for PGx testing was confirmed, venous
blood samples were obtained using EDTA containing Vacutainers. After
receipt of PGx test results and automated reports from the SONOGEN XP
expert system, the clinical pharmacologist and a senior clinical
pharmacist (DN) evaluated all available information and wrote a
comprehensive report for each tested subject. The report included
personalized PGx-based management recommendations for the attention of
patients and treating physicians. If the clinical pharmacologist was in
charge of the patient’s therapy, he would also be able to directly
change the medication. Patients also received a summary of the PGx
profile in a credit card format (supplementary Figure S1 ). If
necessary, there was another follow-up consultation with a personal
discussion of all results and adjustments of pharmacotherapy.