Effectiveness of an Arabic CPIC-Based Pharmacogenomics Microlearning Program on Community Pharmacists' Clinical Decision-Making in Jordan

The total score ranged from 0 to 12, with higher scores indicating better applied PGx clinical decision-making. This outcome was selected as the primary outcome because the intervention was designed to improve pharmacists' applied ability to interpret PGx information and translate it into appropriate medication-related recommendations. The clinical vignette approach allowed assessment of practical decision-making rather than factual knowledge alone.

Immediate post-intervention PGx knowledge scores ranged from 0 to 10, with higher scores indicating greater knowledge.

Change in Pharmacogenomics (PGx) knowledge was calculated by comparing baseline and immediate post-intervention scores using the PGx Knowledge Assessment scale. The scale consists of 10 multiple-choice questions assessing basic PGx concepts and clinical interpretations. The total score ranges from a minimum of 0 to a maximum of 10. Higher scores indicate greater PGx knowledge.

Confidence and readiness scored from 1 to 5. Higher scores indicated greater confidence or readiness. These domains were assessed at baseline, immediately after the intervention period, and at four-week follow-up.

Intervention acceptability outcomes score 1-5, with higher scores indicating greater acceptability.

Contamination and external learning were assessed in both study arms immediately after the intervention period. These outcomes included self-reported access to PGx educational materials outside the study, source of external PGx information, discussion of study content with another participant, and use of PGx decision-support websites or guidelines during the study period. These items were included to identify potential contamination and to support sensitivity analyses where appropriate.

Intervention process outcomes were assessed only among participants allocated to the intervention group. These outcomes included number of completed microlearning modules, completion of case-based questions, and viewing or downloading of the PGx decision checklist.

Major PGx interpretation errors were assessed using responses to the clinical decision-making vignettes that reflected misunderstanding of an important PGx concept or unsafe professional action. The error categories were prespecified according to clinically relevant PGx recommendations and pharmacist practice responsibilities. For clopidogrel-related cases, major errors included failure to recognize that CYP2C19 poor or intermediate metabolizer status may reduce clopidogrel activation and antiplatelet response, thereby requiring communication with the prescriber to consider an alternative antiplatelet strategy when clinically appropriate (Lee et al., 2022). For warfarin-related cases, major errors included failure to recognize that CYP2C9 and VKORC1 variants may influence warfarin dose requirements and anticoagulation risk, as well as the incorrect assumption that PGx results replace INR monitoring; CPIC guidance supports the use of genotype information to guide warfarin dosing when

Four-week retention outcomes evaluate the sustained effects of the intervention measured at the four-week follow-up. This composite outcome utilizes three separate questionnaire domains:

PGx Knowledge Assessment scale: Ranges from a minimum of 0 to a maximum of 10, with higher scores indicating greater PGx knowledge.

Applied PGx Clinical Decision-Making scale (measured via 12 clinical vignettes): Ranges from a minimum of 0 to a maximum of 12, with higher scores indicating better applied PGx decision-making.

Combined Confidence and Readiness scale: Ranges from a minimum of 1 to a maximum of 10, with higher scores indicating a greater level of confidence and readiness to interpret and use PGx information in practice.

Post-study PGx use assessed at four-week follow-up included self-reported PGx-related professional behaviors after study participation.