However, before these relationships could be explored, it was essential to first investigate what was taking place in these pharmacist-patient interactions.The overall aim of this thesis was to investigate the effectiveness of communication between hospital pharmacists and patients during medication counselling.This theory-driven research employed qualitative, quantitative and mixed methods.Communication accommodation theory (CAT) was the theoretical framework invoked to study, analyse and interpret the pharmacist-patient communication exchanges. There are five CAT strategies which measure whether effective communication has occurred: approximation (speech tone, volume, rate, accent), interpretability (using easy-to-understand language, avoiding jargon), discourse management (asking open-ended questions or repairing conversations), emotional expression (appropriate reassurance to patients' concerns) and interpersonal control (strategies to promote equality between speakers and encourage patients to take active roles in managing their healthcare). In this thesis, effective pharmacist-patient communication refers to the extent pharmacists accommodate, or not, to patients' conversational needs based on accommodative behaviour described within CAT strategies.There were two phases to this thesis. The first involved six focus groups (24 pharmacists) from two large metropolitan hospitals. Pharmacists shared their perceptions of their roles and goals in patient medication counselling, and barriers and facilitators in meeting their goals.Audio recorded transcripts were thematically analysed and goals identified by pharmacists were successfully mapped onto the five CAT strategies. Results of phase one helped inform the contents of the semi-structured interview guides utilised in phase two.iii Phase two represented the major portion of this PhD, and took place at a large hospital with multiple specialities. Twelve pharmacists engaged four patients for a total of 48 medication counselling sessions. Each individual session took place first, followed by separate semistructured interviews with pharmacists and patients. Counselling sessions and interviews were audio recorded and observational field notes were taken. Transcribed recordings were selectively coded for the five CAT strategies in pattern-based discourse analysis. Discursis software, as an adjunct to qualitative analysis, was used to visualise pharmacist-patient speech patterns, episodes of engagement and to detect CAT strategies employed by Analysis of the pharmacist-patient counselling sessions revealed that most pharmacists effectively used all five CAT communication strategies during medication counselling sessions as they adapted to patients' conversational needs. Non-accommodation occurred when pharmacists spoke too quickly, used terms not understood by patients, and did not include patients in the initial, agenda-setting phase. Discursis software identified pharmacistpatient engagement episodes, often revealing effectively applied CAT strategies.Semi-structure...