Asthma prescribing and risk of hospital admission: an analysis of linked primary and secondary care records in East London
Inappropriate prescribing in primary care was implicated in nearly half of asthma deaths reviewed in the UK’s National Review of Asthma Deaths (2014). In particular, an excess prescribing of short acting beta2-agonist inhalers (>12 a year SABA), under-prescribing of inhaled corticosteroid inhalers (<12 a year ICS) and solo prescribing of long acting beta2-agonists (LABAs). Research suggests differences in asthma medication use may contribute to asthma morbidity in ethnic minority populations, yet these groups are often under-represented in asthma research. Reports from North America suggest that increasing use of more than 3 SABA inhalers per year is a risk factor for asthma related hospitalisation, with children from inner city areas more likely to have excessive SABA use and five times more likely to be hospitalised for asthma. We report the first UK population-based analysis of asthma prescribing, providing the most recent assessment of risk of hospitalisation for people of ethnic minority backgrounds.
We extracted anonymised EMIS-Web data for 36,126 people with asthma (aged 5-75 years) for one year ending August 2015 across 139 ethnically diverse east London general practices in Hackney, Tower Hamlets and Newham CCGs (total population 942,511). Data was extracted from the North and East London Commissioning Support Unit (NELCSU), which holds hospital Secondary Uses Services (SUS) linked data.
10% (3,671/36,126) people were prescribed >12 SABA inhalers a year, of whom 285 (0.8%) were prescribed >12 a year SABAs as sole treatment. In 105/1,294 cases LABAs were prescribed without an ICS (0.3% total asthma population). 93% of patients had had an asthma review recorded and 82% had an asthma management plan. Multivariate analyses in adults showed risk of admission increased with greater use of SABA inhalers above a baseline of 1-3(4-12 SABA OR 1.73 CI 95% CI 1.20 to 2.49, >= 13 SABA OR 3.26 95% CI 2.05 to 5.17), with increasing BTS step (Step 3 OR 2.78 95% CI 1.73 to 4.47, Step 4/5 OR 9.06 95% CI 5.11 to 16.09) and among Black (OR 2.30 95% CI 1.64 to 3.22) and south Asian adult populations (OR 1.85 95% CI 1.38 to 2.48). Results in children were similar but risk of hospitalisation was not related to ethnic group.
There is a progressive risk of hospital admission associated with the prescription of more than 3 SABA inhalers/year. Adults (but not children) from Black and South Asian groups are at increased risk of hospitalisation for asthma. We support the use of primary care-practice based strategies that electronically detect, monitor and feedback the sub-optimal prescribing of asthma medications to clinicians. No variations were seen in prescribing and management of the adult ethnic minority population with asthma to account for increased risk of admission. Further work is needed to target these at-risk groups.