What happens between first symptoms and first acute exacerbation of COPD? Mapping and prediction study

Date of Approval
Application Number
19_116
Technical Summary

Aims and objectives: To describe and model the patient journey from symptom presentation to diagnosis and first acute exacerbation for COPD patients in England. This will include examining variations by Clinical Commissioning Group, GP practice and time period, followed by the construction and validation of a risk prediction or risk trajectory model for the first AECOPD.

Methods: Using the Clinical Practice Research Datalink (CPRD) and two cohorts ten years apart, we will describe the management of the patient following initial presentation with symptoms through to their diagnosis of COPD and their first AECOPD, which for some patients will be the same event. Given that COPD can present differently depending on comorbidity, the mapping will be described separately for people with asthma and heart failure in particular. The second part will model the risk of the first AECOPD using factors such as airways obstruction, age, smoking, BMI, gender, comorbidities and public data on temperature and pollution. This will use logistic regression, random forests and cause-specific hazards modelling. Predictors will be ranked in importance from GP, patient and system perspectives. Models will be externally validated using CPRD “Aurum” practices.

Anticipated impact and dissemination: This study will fill key gaps in our understanding of how patients obtain their COPD diagnosis (their “route to diagnosis”), how they are managed in primary care, and how they get their first AECOPD. Comparisons between the two time periods will highlight what has changed and inform NHS preparation for future needs regarding COPD. A risk prediction model for first acute exacerbation will aid shared decision-making between GPs and patients and facilitate early intervention; ranking the predictors will suggest priorities for action.

Health Outcomes to be Measured

• Setting where COPD first recorded (primary or secondary care)
• Time from symptom presentation in primary care (where known) to diagnosis
• First acute exacerbation (AECOPD)

Collaborators

Alex Bottle - Chief Investigator - Imperial College London
Alex Bottle - Corresponding Applicant - Imperial College London
Azeem Majeed - Collaborator - Imperial College London
Jennifer Quint - Collaborator - Imperial College London
Susan Nunn - Collaborator - Imperial College London

Linkages

HES Accident and Emergency;HES Admitted Patient Care;HES Outpatient;ONS Death Registration Data;Practice Level Index of Multiple Deprivation;Non-standard