Exploratory research in clinical and social pharmacy
Prescribing for the patient and the planet: a pragmatic feasibility study of a behaviour change intervention to reduce liquid amoxicillin prescribing in primary care
By Rathbone AP, Pickles J, Griffiths ML and 4 others.
Abstract
Background
Oral liquid medicines can be clinically appropriate but may be used when solid oral formulations are feasible, with implications for medicine costs and environmental sustainability. We evaluated the feasibility of GPILL, a theory-informed intervention using prescribing feedback, social norms and information on formulation-associated carbon dioxide equivalent (CO₂e) emissions to support reduced liquid amoxicillin prescribing in primary care.
Methods
The intervention was called 'GPILL' which stands for a 'Green Prescribing Intervention to Lower Liquids' and was adapted from an existing prescribing feedback intervention based on social normalisation theory which incorporated social-norm feedback. Delivered as an emailed PDF of a letter, the intervention incorporated information about levels of prescribing of the practice in comparison to other practices in the area, the environmental impact of liquid formulations and guidance on supporting patients to swallow capsules rather than use a liquid formulation. A quasi-experimental before-and-after design was used for practices in one geographical area of England. Rates of amoxicillin liquid prescribing were compared to capsules for all practices to generate a ratio of liquid: solid prescribing. Practices in the top 50% received the intervention (n = 28); whilst the remaining practices acted as controls (n = 26). No patient-level inclusion or exclusion criteria were applied to the practice. Prescribing volumes were obtained from OpenPrescribing, with data extrapolated to calculate costs and carbon dioxide equivalents of a standard course of treatment, using published costs and UK conversion factors.The primary outcome was to assess the feasibility of the intervention. Secondary outcomes were number of liquid and solid prescriptions, prescribing costs and formulation-associated CO₂e. Outcomes were assessed using routinely collected prescribing data during winter months (December-February) from 2020 to 2024. No deviations from planned outcomes were reported.