Mapping the Processes of Pharmacist Therapeutic Reasoning: A Scoping Review and Development of the Pharmacist Therapeutic Reasoning Model.

Background: Pharmacists make complex therapeutic decisions. Yet the reasoning processes that result in these choices, therapeutic reasoning (TR), are poorly defined. Existing models of clinical reasoning often overlook how pharmacists weigh risks and benefits of treatment options.

Aim: To develop a conceptual model that characterizes the processes, subprocesses, and cognitive strategies used during pharmacist TR based on current literature.

Methods: A scoping review was conducted in February 2024 to identify studies describing pharmacist or pharmacy student reasoning during therapeutic decision-making. Data were extracted by two researchers using a standardized form and inductively analyzed. Codes were thematically organized based on shared properties: discrete knowledge, reasoning connections, or modifying influences. Theory use was assessed using the Continuum of Theory Talk framework.

Results: Ten studies met inclusion criteria representing diverse contexts, scope, and reasoning stimuli. A total of 109 unique codes were identified and synthesized into a conceptual pharmacist therapeutic reasoning model (Pharm-TRv1). It consists of three knowledge domains (drug, disease, and patient information), three core reasoning processes connecting these domains (drug-patient, drug-disease, patient-disease), and three to four related subprocesses. The model includes five influencing factors: two external (decision context and entry and exit from reasoning) and three internal cognitive modifiers (metacognition, closing a knowledge gap, and reflection).

Conclusion: Pharm-TRv1 provides a foundational model of pharmacist therapeutic reasoning grounded in current literature. It offers a structured way to describe, teach, and study how pharmacists evaluate treatment options. Future research should further explore specific processes and subprocesses, validate the model, and explore broader theoretical perspectives.