By using recent data on hospital attendance and COVID-19 laboratory tests, available within two NHS trusts in Nottingham and Cardiff we will enable the calculation of the risk of developing COVID-19 infection after attending an outpatient hospital appointment. This will assist in the restart planning when resuming face to face outpatient radiology appointment.

Since March 2020, the novel coronavirus (COVID-19) pandemic has caused considerable disruption to the provision of routine healthcare in the UK. A key priority for healthcare providers when gaining control of COVID-19, is to restart the provision of urgent non-COVID care. There are several barriers including a reluctance for people to attend hospital appointments for fears of contracting COVID-19. Although SARS-COV2 infections have been reported to occur during hospital inpatient stay, the risk of acquiring SARS-COV2 during outpatient consultations or radiological investigations has not been reported.

In a pilot study at our hospitals during the pandemic, we have found radiology to reliably record in person attendance contrary to outpatient clinic appointments records that were contaminated by remote consultations. The investigators will calculate the incidence of infection in approximately 30,000 patients at Nottingham and 17,000 patients at Cardiff and calculate the risk of infection within 28 days of attending outpatient radiology appointments. Controls will use data on patients who attended the hospitals in 2019.

The study team will utilize the data held in the electronic systems of NUH and University Hospital of Wales to perform a cohort study which will comprise both an exposed cohort and unexposed cohort.

The exposed cohort will comprise patients who attended outpatient radiology appointments during (between 29/1/20 - 24/5/20) and whether they subsequently developed a positive or negative PCR test for Sars-CoV2 result within 28-days of their attendance. The unexposed cohort will work as a control group, comprising individuals who attended outpatient radiology appointments during the equivalent period in 2019.

All of this data will be retrospective, so will not require any additional data collection, nor will it interfere with routine clinical care. Pseudo-anonymised data will be transferred from University Hospital of Wales in Cardiff to Nottingham University Hospitals (NUH) Trust via a password-protected, encrypted spreadsheet, with original patient identifiers removed, and a unique code assigned, that only the researcher in Cardiff can use to trace back to the individual, this is so all the analysis can be performed at NUH by a Nottingham based statistician.

The study team consisting of clinicians, data analysts, epidemiologist and clinical researchers will analyse this information to quantify the risk of infection which will help inform the recovery plans and service provision during the restart of urgent and routine non-COVID care.

Inclusion Criteria:

Exposed Cohort: outpatient radiology attendance at NUH between 29/1/20 - 24/5/20 or at University Hospital of Wales, Cardiff between 7/3/20 - 11/5/20.

Unexposed Cohort: outpatient attendance outpatient attendance at NUH between 29/1/19 - 24/5/19 or at University Hospital of Wales, Cardiff between 7/3/19 - 11/5/19.

Exclusion Criteria:

Patients who had an inpatient stay in the previous 28-days but excluding the 2 days prior to the SARS-COV2 test Radiological examinations that were part of an inpatient stay were not considered

All individuals attending outpatient clinics will be included for analysis, this is anticipated this to be in excess of 30,000 patients at NUH and around 17,000 patients at Cardiff. To ensure a substantive number of patients are included for analysis and comparison across the UK, 2 large hospitals (Nottingham University Hospitals and Cardiff University Hospitals) will be participating in this study.