Identifying and measuring important outcomes for evaluating the impact of pharmacist prescribing in Ireland: A modified Delphi study

Background: Pharmacist role expansion, including pharmacist prescribing, is increasing globally. Assessing the impact of such role expansion is vital to understand whether it achieves its intended goals. Purpose: To identify key outcomes to evaluate pharmacist prescribing within Ireland's planned Common Conditions Service (CCS) and independent pharmacist prescribing contexts, and determine their measurability using existing health data sources. Methods: In a three-round Delphi study, an expert panel (including patients) rated the importance of outcomes, pre-identified via a rapid overview of reviews, using Likert scales.Outcomes reaching consensus for inclusion (rated by ≥75% as critically important) or exclusion (<25%) after the second round were not re-rated. In the third round, remaining outcomes were re-rated and experts also rated the feasibility of measuring each outcome using existing health data sources. Results: Thirty experts completed all rounds. For CCS, seven outcomes reached consensus as critically important: "Patient experience and satisfaction", "Access to care", "Guideline concordance", "Symptom improvement, or clinical cure", "Re-consultation with other healthcare providers", "Cost of care to the healthcare system", and "Referral to other healthcare providers". For other independent prescribing contexts, ten outcomes were critically important, including "Mortality", "Clinical effectiveness", "Adverse events", and "Cost of care to patients". Important CCS outcomes varied in their measurability using existing data, with 'Prescribing rate' (76% agreement) and 'Cost to patients' (64%) and 'Cost to patients' (64%) were most feasible. Conclusions: This study identified priority outcomes for evaluating the impact of pharmacist prescribing and their measurability, encompassing clinical, safety, economic, and patient perspectives.