Abstract

Introduction

Metered Dose Inhalers (MDIs) account for 3% of NHS carbon emissions. In April 2022, NHS England introduced a 12-month payment-by-results scheme focussed on reducing carbon emissions from inhalers. It rewarded Primary Care Networks (PCNs) for reduction in:
-MDI preventers (C3)
-Salbutamol mean carbon emissions (by increased use of SABA DPI (C1) and lower carbon SABA MDI (C2))

Indicators C1, C2 and C3 were added to the newly created national dashboards along with C4, which focuses on reducing high-carbon preventer MDIs.

Methods

This project analysed routinely collected national prescribing data to assess the impact of the financial incentive and the introduction of dashboards on environmental inhaler prescribing. Changes in prescriptions issued between January-March 2022 versus January-March 2023 were calculated for all four comparators. Linear regression models were performed with potential predictors, such as asthma and COPD prevalence, GP electronic system, list size, ICS (Integrated Care System), PCN, appointment mode and population deprivation index.

Results

Comparators C1 and C3 showed minimal positive changes in prescribing, with mean increases of 0.64 and 1.73 DPI inhalers per 1,000 patients, respectively. Comparator C2, involving salbutamol MDI swaps (mainly Ventolin to Salamol), showed significant improvement, with 8.11 new inhalers prescribed per 1,000 patients. The reduction in C4, which was not supported by the payments scheme, was unsuccessful, showing a slight increase of 0.19 inhalers per 1,000 patients, opposite to the expected direction.

Among the predictors analysed in linear regressions, only the PCN and ICS (Fig.1) demonstrated high performance and significance across C1-C4 (R-squared= 0.61, p<0.001 for C2). The two predictors had perfect multicollinearity.

Conclusions

The financial incentive had negligible effect on environmental prescribing changes for comparators requiring face-to-face patient education on new inhaler techniques (C1,C3,C4). When the inhaler swap did not necessitate introducing a new device and patient education (C2), the incentive was more effective.