Figure 2. Available Pharmacogenomic Information Impacts Major Prescription Decisions.

Medication changes at all study visits where providers accessed pharmacogenomic results via GPS are depicted. In the center of each diagram, the total number of medication changes of each type are shown (2A=visits with drug discontinuations; 2B=visits with new medications prescribed; 2C=visits with dose adjustments). The first concentric circle then divides the total number of medication changes into categories based on whether pharmacogenomic information was available within the GPS (beige represents drugs without pharmacogenomic information; green/yellow/red represent drugs with each of these respective pharmacogenomic alert types). The outermost concentric layer (orange) indicates the proportion of those medication changes, stratified by green/yellow/red alert level, that were attributed through a formal evaluation process as being influenced by the pharmacogenomic information. 2A - Drug Discontinuations. There were 161 drug cessations during the study period at visits where providers accessed the GPS. While about half (n=89, 55%) of these discontinued medications did not have pharmacogenomic information, when pharmacogenomic signals were available (9 + 42 + 21=72), a large majority (44/72=61%) of provider decisions to stop drugs were influenced by the provided pharmacogenomic recommendations. 2B – New Medications Prescribed. There were 286 new drugs prescribed during study visits where providers accessed the GPS. While the majority of these new prescriptions did not have pharmacogenomic information (n=190), for those that did (24+72=96), physicians reported that the decision to prescribe the ultimately chosen drug was affirmatively influenced by pharmacogenomic information in 50% (48/96) of cases. 2C - Dose Adjustments. There were 136 dose changes at visits when providers accessed the GPS during the study period. The majority of dose-adjustments that occurred in drugs with pharmacogenomic information were for green light drugs (n=31), although yellow (n=11) and red light medication (n=2) dose-adjustments were observed. Altogether, 23% (10/44) provider decisions to make dose changes in drugs with viewed pharmacogenomic information were influenced by GPS recommendations. GPS=Genomic Prescribing System.