Representativeness, vaccination uptake and COVID clinical outcomes 2020-21 in the UK’s Oxford-RCGP Research and Surveillance Network: cohort profile. (Preprint)

Abstract

The Oxford-Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) is one of Europe’s oldest sentinel systems, working with the UK Health Security Agency (UKHSA) and its predecessor bodies for 55 years. Its surveillance report now runs twice weekly, supplemented by online observatories. In addition to conducting sentinel surveillance from a nationally representative group of practices, the RSC is now also providing data for syndromic surveillance.

Describe the cohort profile at the start of the 2021-2022 surveillance season and changes to our surveillance practice.

The RSC’s pseudonymised primary care data, linked to hospital and other data, are held in the Oxford-RCGP Clinical Informatics Digital Hub (ORCHID), a trusted research environment (TRE). We describe the RSC’s cohort profile as of September 2021, divided into a primary care sentinel cohort (PCSC) - collecting virological and serological specimens - and a larger group of syndromic surveillance general practices (SSGP). We report changes to our sampling strategy that brings the RSC into alignment with European Centre for Disease Control (ECDC) guidance and then compare our cohort sociodemographic characteristics with Office for National Statistics (ONS) data. We describe influenza and COVID-19 vaccine coverage for the 2020-21 season (week 40, 2020 to week 39 2021), the latter differentiated by vaccine brand. Finally, we report COVID-19 related outcomes in terms of hospitalisation, intensive care unit (ICU) admission, and death.

As a response to COVID-19, RSC grew from just over 500 PCSC practices in 2019 to 1,879 practices (PCSC=938, SSGP=1,203). This represents 28.6% of English general practices and 31% of the population (N=17,560,196). In the reporting period, the PCSC collected >8,000 virology and >23,000 samples. The RSC population was found to be broadly representative of the national population in terms of age, gender, ethnicity, NHS Region, socioeconomic status, obesity and smoking habit. The RSC captured vaccine coverage data for influenza (n=5.4m), and COVID-19; reporting dose one, (n=11.9m), two (n=11m) and three (n=0.4m) for the latter as well as brand-specific uptake data (AstraZeneca vaccine [n=11.6m], Pfizer [n=10.8m] and Moderna [N=0.7m]). The median (and interquartile ranges) for COVID Hospitalisation and ICU admissions for COVID, were 1181/week (559-1559/week) and 115/week (50-174/week) respectively.

The RSC is broadly representative of the national population, its PCSC is geographically representative. Its SSGPs are newly supporting UKHSA syndromic surveillance efforts. The network captures vaccine coverage and has expanded from reporting primary care attendances to hospital outcomes and death. The challenge remains to increase virological and serological sampling to monitor the effectiveness, and waning of the increasing range of vaccines available in a timely manner.