ObjectivePolypharmacy occurs in approximately 30% of older adults aged 65 years or more, particularly among those with multimorbidity. With polypharmacy, there is an associated risk of potentially inappropriate prescribing (PIP). The aims of this scoping review were to (1) identify the intervention elements that have been adopted to reduce PIP in the outpatient setting and (2) determine the behaviour change wheel (BCW) intervention functions performed by each of the identified intervention elements.DesignScoping reviewData sourcesPubMed, Cumulative Index to Nursing and Allied Health Literature, EMBASE, Web of Science and Cochrane Library databases, grey literature sources, six key geriatrics journals and the reference lists of review papers.Study selectionAll studies reporting an intervention or strategy that addressed PIP in the older adult population (age ≥65) with multimorbidity in the outpatient setting and in which the primary prescriber is the physician.Data extractionData extracted from the included studies can be broadly categorised into (1) publication details, (2) intervention details and (3) results. This was followed by data synthesis and analysis based on the BCW framework.ResultsOf 8195 studies yielded, 80 studies were included in the final analysis and 14 intervention elements were identified. An average of two to three elements were adopted in each intervention. The three most frequently adopted intervention elements were medication review (70%), training (26.3%) and tool/instrument(s) (22.5%). Among medication reviews, 70% involved pharmacists. The 14 intervention elements were mapped onto five intervention functions: ‘education’, ‘persuasion’, ‘training’, ‘environmental restructuring’ and ‘enablement’.ConclusionPIP is a multifaceted problem that involves multiple stakeholders. As such, interventions that address PIP require multiple elements to target the behaviour of the various stakeholders. The intervention elements and their corresponding functions identified in this scoping review will serve to inform the design of complex interventions that aim to reduce PIP.