Table 1.

Data sources

Data set	Coverage	Key information (including coding system)
Primary care
CPRD Aurum	Start of patient GP registration – c. October 2020	Symptoms and clinical diagnoses, demographic characteristics, vaccination history, lifestyle and behaviours (e.g. smoking history), laboratory test results, prescriptions, referrals to secondary care (SNOmed codes, READ codes)
Linked data sets
ONS Death registration data	1998–2020	Date, place and cause of death including underlying and contributory causes of death (ICD-10)
Hospital Episode Statistics (HES)
Admitted Patient Care (APC)	1997–2020	Details of all admissions to NHS hospitals in England (including acute, mental and primary care trust hospitals) including clinical diagnoses (ICD-10) and procedures performed (OPCS)
Diagnostic Imaging Dataset (DID)	2012–2020	Type of imaging performed (CT, X-ray, MRI) and body area imaged (e.g. chest)