------------------------- COVID-19 Vaccination Effectiveness -----------------------------------

-- Author: NHS England and Improvement Performance Analysis Team - April 2021

-- Email: england.NHSEI-advanced-analytics@nhs.net

-- github: https://github.com/NHSEI-Analytics

-- Summary: The analysis here contributes to an NHS England and Improvement study on COVID-19 vaccine effectiveness. -- For more information please see the pre-publication version of the study:

-- Disclaimer: This is a simplified version of the work used for the final analysis.
-- Record level data is used in the final analysis which has been suppressed in this script. -- File locations and database directories have been suppressed behind temp databases.

-- The analysis is split into 3 sections:

• 01 Pairwise Matching Applies the pairwise matching process to vaccination data. Matching vaccinated individuals to unvaccinated individuals on a number of criteria.

• 02 Matched AE APC Join Takes the matched patients and joins any AE / APC hospitalisation records with COVID-19.

• 03 Bootstrapping Adjustment Applies bootstrapping and an adjustment methodology to the matched data, for positive tests, AE admissions and APC admissions. Outputs summary tables to excel for use with the publication.