Unmet Need and Time Waiting for Intervention with Specialist Therapy in Asthma

Date of ISAC Approval: 
Lay Summary: 
This study will investigate the time that patients with asthma wait to see a specialist physician and potential reasons why there may be a delay in seeing a specialist. This will be done by calculating the time between prescriptions and clinical events associated with a patient requiring specialist review and a record of a referral to a specialist. This information will then be analysed to understand which factors are most important in impacting the waiting time. Asthma management is mostly based on a treatment add-on approach in which higher doses and higher numbers of drugs are prescribed as symptoms continue. Because of this, deciding when an asthma patient needs to be managed by a specialist is more complicated to determine compared to some other diseases. The study to be undertaken could help establish which factors may be barriers to specialist care. This would inform health care organisations as a whole and potentially specialist and general practitioners.
Technical Summary: 
This study is a non-interventional cohort study using existing data provided by the Clinical Practice Research Datalink (CPRD), to gain detailed insights on the waiting time between eligibility and for referral to secondary care for patients treated with additional therapies for asthma. The drivers of a potential delay in referral to secondary care management have yet to be investigated. The main objective of this study is to describe the time to referral and understand the factors associated with length of time waiting for referral to secondary care. Comorbidities and demographic information will be described for the groups of patients initiated on different therapies and survival analysis will be used to estimate the average time to referral and associated risk factors for delay. The results from this study will be used to support the scientific understanding of how therapy guidelines are adhered to in primary care.
Health Outcomes to be Measured: 
- For patients eligible for referral, the time to first respiratory out-patient visit/referral - The association between medication use and asthma control - Average GP visit duration - The proportion of patients meeting the criteria for specialist referral - The proportion of patients referred to respiratory outpatients - Rate of GP visits - Patterns of use of chronic medication for patients receiving high dose therapies - Factors related to asthma management in secondary care - Rate of hospital admissions - Rate of short-acting therapies prescriptions - Rate of referrals

Dr Chris Poole - Chief Investigator - Boehringer-Ingelheim - UK
Alicia Gayle - Corresponding Applicant - Imperial College London
Birgit Voelker - Collaborator - Boehringer-Ingelheim International GmbH
Gavin Chiu - Collaborator - Boehringer-Ingelheim Pharmaceuticals, Inc
Dr John Blakey - Collaborator - University of Nottingham
Michael Baldwin - Collaborator - Boehringer-Ingelheim International GmbH
Nikco Hau - Collaborator - Boehringer-Ingelheim Germany

HES Admitted;HES Admitted;HES Outpatient;HES Outpatient;Patient IMD;Patient IMD