Consultations for non-specific symptoms commonly reported with COVID-19 and other acute respiratory infections in the Clinical Practice Research Datalink: long term trends and patient characteristics

Date of ISAC Approval: 
05/05/2020
Lay Summary: 
COVID-19 is an infectious respiratory disease caused by a novel coronavirus. Since November 2019, over 1.9 million people have been infected worldwide and as of April 2020 over 121,000 deaths have occurred. COVID-19 has been compared to seasonal flu because some of the initial symptoms of infection include fever, cough, fatigue and muscle pain. Anonymised primary care patient data from the Clinical Practice Research Datalink (CPRD) have been previously used to understand the burden of respiratory viral illness on the health care system, predict whether infections may result in hospitalisation and deaths and to determine who may be at risk for these outcomes. In the context of the current COVID-19 pandemic, it has the potential to provide important data about high risk and vulnerable populations and the potential disease burden among such patients. This descriptive study will assess weekly and monthly trends in the diagnosis of fever, cough, fatigue and muscle pain recorded in primary care patient records during 01/01/2015 – 30/04/2020. This information may be important in estimating undiagnosed mild COVID-19 infection in the period leading up to the COVID-19 pandemic. Trends will also be described by age group, gender, level of socioeconomic deprivation, region and rural/urban location. We will also describe pre-existing health conditions among patients with at least one symptom and examine their use of health service during the pandemic. Findings from this study will illustrate how primary care data can be used in other research to inform health care planning, including how health measures may be targeted.
Technical Summary: 
We will use CPRD primary care data to estimate weekly and monthly consultation rates for fever, cough, and fatigue or myalgia during 01/01/2015 – 30/04/2020. These non-specific symptoms are reportedly common in COVID-19 and other acute respiratory infections. The rates may be useful for modelling excess recording consistent with undiagnosed mild COVID-19 cases in the early phases of the UK outbreak. Consultation rates and 95% confidence intervals for each symptom will be generated and stratified by gender, age band, level of social deprivation, region and rural/urban location. The demographic and clinical characteristics of patients with at least one respiratory infection symptom recorded during each flu season in the study period, including the 2019/2020 flu season, will also be described. Pre-existing comorbidities including respiratory and cardiovascular conditions will be based on Read coded Quality Outcomes Framework definitions used in primary care and International Classification of Disease codes (ICD-10) for hospital data in secondary analysis. Prescribing of respiratory, cardiovascular and immunosuppressing medications as well as use of health services before and during the pandemic period will also be evaluated. In March 2020, GP software providers introduced specific COVID-19 clinical codes, including suspected and confirmed diagnoses. Anecdotal reports suggest that prior to this time GPs may have used existing coronavirus codes to record information about COVID-19 cases. We will explore patterns of recording of COVID-19 and coronavirus codes, and if numbers permit, we will describe demographic, clinical characteristics, and presenting symptoms of patients with one of these codes recorded from January 2020. Findings from this study will illustrate the potential for primary care data for research to inform health care planning and monitoring, as well as disease modelling.
Health Outcomes to be Measured: 
Primary: - Weekly and monthly consultation rates for fever, cough, and fatigue or myalgia in CPRD GOLD and CPRD Aurum, stratified by age group, gender, level of social deprivation, practice region and rural/urban classification. Secondary: - Demographic and clinical characteristics including comorbidities, prior prescribing and health care resource use, in patients with fever, cough, and fatigue or myalgia during the 2019/20 flu season. - Weekly consultation rates for COVID-19, based on specific codes introduced during March 2020, or relevant existing coronavirus codes, from January 2020 onwards. - Demographic and clinical characteristics and presenting symptoms of patients with a specific COVID-19 diagnosis, or relevant coronavirus code from January 2020 onwards.
Collaborators: 

Puja Myles - Chief Investigator - CPRD
Achim Wolf - Collaborator – CPRD
Daniel Dedman - Collaborator - CPRD
Janet Valentine - Collaborator - CPRD
Tarita Murray-Thomas - Corresponding Applicant - CPRD
Tim Williams - Collaborator - CPRD

Linkages: 
2011 Rural-Urban (Non-standard) LSOA;HES A&E;HES Admitted;Patient IMD;Practice IMD (Standard)