Prevalence of Poorly Controlled Asthma and Factors Associated with Specialist Referral in Those with Poorly Controlled Asthma in a Paediatric Asthma Population

Abstract

Background

Significant morbidity and mortality are associated with poor asthma control. The aim of this study was to determine factors associated with poor control and referral to specialist secondary care services.

Methods

We used primary care data from the Clinical Practice Research Datalink Aurum (CPRD) linked with Hospital Episode Statistics (HES) records from 1st January 2007 to 31st December 2019. We selected patients aged 6–17 years old. Poor control was defined as six or more prescriptions of short-acting beta-agonist (SABA) inhalers, two or more courses of oral corticosteroids (OCS), an Asthma Control test (ACT) or childhood ACT <20, one hospital admission for asthma, or one visit to Accident & Emergency (A&E) department for asthma-related episodes in the 12 months following asthma diagnosis. Asthma severity was defined following GINA guidelines 2021.

Results

About 17.6% of children aged between 6 and 17 years with active asthma had poor control. Severe asthma, eczema, food allergies, increased BMI and living in deprived areas were identified as risk factors for poor control. Among those with poor control, referral rates to specialist care were extremely low, only 2% overall. Those with severe asthma were three-times more likely to be referred than those with mild-to-moderate asthma [HR_crude = 4.04 (95% CI, 3.35–4.87); HR_adj = 2.72 (95% CI: 2.13–3.49)]. Other factors associated with referral were food allergy and living in a more deprived area.

Conclusion

Around 1 in 6 children and adolescents with active asthma are not achieving adequate control of their symptoms. Among the subset of 6–17-year olds with poorly controlled asthma, timely referral for specialist advice in secondary care is rare, especially in those with so-called mild asthma who nevertheless are at significant risk for poor asthma outcomes.

Keywords:

• asthma
• poor control
• referral to specialist

Data Sharing Statement

This study used existing data from the UK CPRD electronic health record database, this data resource is accessible only to researchers with protocols approved by the CPRD’s independent scientific advisory committee; therefore, no additional unpublished data are available. All data management and analysis computer code are available on request from the corresponding author.

Linked pseudonymised mortality data from the Office for National Statistics (ONS), socioeconomic data from the Index of Multiple Deprivation (IMD), and secondary care data from Hospital Episode Statistics (HES) were provided for this study by CPRD for patients in England. Data is linked by NHS Digital, the statutory trusted third party for linking data, using identifiable data held only by NHS Digital. Select general practices consent to this process at a practice level, with individual patients having the right to opt-out. Use of HES and ONS data is Copyright © (2018), re-used with the permission of The Health & Social Care Information Centre, all rights reserved.

Data are available on request from the CPRD. Their provision requires the purchase of a license, and this license does not permit the authors to make them publicly available to all. This work used data from the version collected in October 2020 and have clearly specified the data selected in the Methods section. To allow identical data to be obtained by others, via the purchase of a license, the code lists have been provided on GitHub. Licenses are available from the CPRD (http://www.cprd.com): The Clinical Practice Research Datalink Group, The Medicines and Healthcare products Regulatory Agency, 10 South Colonnade, Canary Wharf, London E14 4PU.

Acknowledgments

ConstantinDeos Kallis and Ann Morgan are co-first authors for this study. We would like to acknowledge Carmen Amarfei for her input in early manuscript drafts.

Authors and Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

AM and CK have nothing to declare. JKQ reports grants from AUK-BLF, Asthma+Lung UK, MRC, The Health Foundation, Health Data Research UK; grants and personal fees from AZ, BI, GSK, Bayer, grants from Chiesi, outside the submitted work. LF reports grants from AUK, NIHR and personal fees from AZ, Sanofi, Novartis and GSK outside the submitted work. The authors report no other conflicts of interest in this work.

Additional information

Funding

There is no funding to report.