Objectives The role of clinical pharmacists in hospitals has evolved and continues to expand. In the UK, outside of a few national policy drivers, there are no agreed priorities, measures or defined outcomes for hospital clinical pharmacy (CP). This paper aims to (1) highlight the need to identify and prioritise specific CP roles, responsibilities and practices that will bring the greatest benefit to patients and health systems and (2) describe systematic weaknesses in current research methodologies for evaluating CP services and propose a different approach.

Method Published reviews of CP services are discussed using the Economic, Clinical and Humanistic Outcomes framework. Recurring themes regarding study methodologies, measurements and outcomes are used to highlight current weaknesses in studies evaluating CP.

Results Published studies aiming to demonstrate the economic, clinical or humanistic outcomes of CP often suffer from poor research design and inconsistencies in interventions, measurements and outcomes. This has caused difficulties in drawing meaningful conclusions regarding CP’s definitive contribution to patient outcomes.

Conclusion There is a need for more research work in National Health Service (NHS) hospitals, employing a different paradigm to address some of the weaknesses of existing research on CP practice. We propose a mixed-methods approach, including qualitative research designs, and with emphasis on cost-consequence analyses for economic evaluations. This approach will provide more meaningful data to inform policy and demonstrate the contribution of hospital CP activities to patient care and the NHS.