Table 1.

Codebook used during the “Think Aloud” session to help categorize the statements the healthcare providers provided on the two PGx-CDS.

Coding Category	Definition
Usability	Ease of use of the CDS tool, ability to use with minimal effort. This can be both positive and negative (usability errors).
Visibility	Ability to quickly recognize key messages and instructions provided by the CDS tool. Colors and symbols are examples of how messages can be easily recognized in the CDS.
Workflow	Ability of the CDS tool to fit into the natural order of events in a patient encounter.
Content	Medical accuracy or appropriateness of CDS tool text included as orders, patient information, documentation.
Understandability	Ability to quickly comprehend meaning of text, instructions, and the purpose of CDS components.
Medical Usefulness	Improves clinical decision-making during encounter.
Navigation	Ability to move easily through the CDS tool.