Deprescribing and medicines optimisation, two sides of the same coin? Considerations for design of interventional studies.

Interventions to promote deprescribing are an important focus of research. Key decisions for such interventions are whether to target one or multiple medicines, and whether the intervention scope is deprescribing, or also extends to other aspects of medicines optimisation. This article reflects on how these decisions impact on developing interventions and measuring outcomes. Many behavioural strategies are common to deprescribing and medicines optimisation, however operationalisation may differ. Aspects to consider include the burden of multiple simple interventions versus one complex intervention, the extent to which the approach to deprescribing can be specified as part of the intervention, and variability in how the intervention is delivered across patients and providers. Outcomes should be selected based on the intervention target and scope and the audience for whom evidence is being produced. These may include medication changes, and process outcomes to assess intervention delivery. Targeting single medications may allow for a focus on specific clinical or symptom-related outcomes, but a broader perspective may be needed in a generalist setting in the context of multimorbidity and which also considers the patient's priorities. Cost-related outcomes are also important to inform implementation decisions, and modelling approaches may be more feasible for interventions targeting single medications.