Impact of regional asthma guidelines on SABA prescribing patterns across England: an interrupted time series analysis.

The 2024 British Thoracic Society/ National Institute for Health and Care Excellence/ Scottish Intercollegiate Guidelines Network asthma guidelines recommend anti-inflammatory reliever (AIR)-based management, providing opportunity to reduce short-acting beta agonist (SABA) over-use. Many English regions also publish local guidelines. Analysis of 34 regional guidelines enabled grouping into three categories: SABA-first, inhaled corticosteroid (ICS) plus SABA and AIR (as-needed AIR), based on recommended initial treatment. Interrupted time series analysis using publicly available data demonstrated that AIR guideline publication resulted in the greatest decline in SABA prescribing, expressed as the proportion of all ICS-containing and SABA inhaler prescriptions (AIR: -0.26% (SD 0.09%) per month; SABA-first: -0.1% (SD 0.03%) per month, p=0.001 vs AIR; and ICS plus SABA: -0.16% (SD 0.06%) per month, p=0.004, vs AIR). Therefore, regional guidelines do affect local prescribing practice and alignment with the latest national recommendations could improve asthma prescribing and resulting patient outcomes.