Identifying patients for inclusion in the SPL requires interrogation and analysis of multiple national datasets collected by NHS Digital. These include:
- Hospital Episode Statistics (HES)
- Primary Care Prescribed Medicines (PCPM)
- Personal Demographics Service (PDS)
- Maternity Services Dataset (MSDS)
- GP data one-off extract based on seasonal influenza vaccination algorithm (GPFLU)
- GP data weekly extract based on COVID-19 SPL inclusion criteria (GPSPL)
HES data, specifically Admitted Patient Care (inpatient) records, were extracted for the period 1 June 2010 to 29 February 2020 inclusive, with the exception of patients with admission for lung neoplasm and radiotherapy (Table 2, Rule 1) where all records were extracted from 2006 onwards (the point at which ICD-10 coding was introduced for this disease group).
Further details regarding HES data and ICD-10 (plus OPCS-4 coding) can be found in Annex A.
PCPM data were extracted at the time of use from the NHS Business Services Authority (NHSBSA) and covered the period 1 September 2019 to 29 February 2020, which represents the latest 6 months of data available for use.
Data up to and including 31 March 2020 was used for MSDS, recognising that given recent changes to how these data are collected, and the data model therein, data quality and coverage is limited.
Data up to and including 19 March 2020 was used for GPFLU. This is specifically the extract based on seasonal influenza vaccination algorithm that includes all coded data identified by the algorithm. These are data that reference the “At Risk” group highlighted in section 1.
Data up to and including 20 May 2020 was used for GPSPL. This is specifically the extract based on COVID-19 SPL inclusion criteria, but also includes moderate and low risk flags that would signal exclusion, or removal, from the SPL.
All data were extracted from NHS Digital’s data repositories on 19 March 2020.