Medical certificates, also known as fit notes or sick notes, are important documents issued by healthcare professionals (e.g., doctors, nurses, etc) to explain how an individual’s health condition may limit their ability to work. Changes in how these fit notes are issued and why can help us understand health trends in society over time, spot public health issues and thus decide where to prioritise resources. There is currently a lack of research investigating the issuing of fit notes in primary care, especially in the context of significant medical, psychological, social and economic change due to public health events like the COVID-19 pandemic.
Our study aims to look at the fit notes issued to the working-age population (aged between 18 and 65) and the economic costs associated with being off work, both before and during the latter part of the COVID pandemic, using primary care medical certificate data. We will also explore if the rate of fit notes issued varies by different patient-related factors like age, sex, ethnicity, poverty, smoking, body mass index (including obesity), health condition, number of consultations, and region. Finally, we will investigate which health problems cause most of the sickness absence in the working-age population. This study will inform public health planning and policy making, ensuring we are better prepared for the transition in sickness absence in the post-pandemic era and for potential future pandemics.
People have experienced significant medical, psychological, social, and economic changes since the COVID-19 pandemic including changes to working practices. There is little research on sickness absence in the UK working-age population using healthcare record data and the picture of how sickness absence has changed following the COVID-19 pandemic is still unclear, indicating a significant research gap. This study aims to explore all-cause sickness absence (as measured by fit notes: official medical certificates issued by health professionals in the UK to indicate an individual's inability to work due to sickness after 7 days of sickness absence) among the working-age population (aged between 18 and 65) in England before and during the latter part of the COVID-19 pandemic. This retrospective cohort study will use healthcare record data from a large primary care database, CPRD Aurum, covering the period both before the COVID-19 pandemic (from 1st January 2017 to 31st December 2019) and during the latter part of the pandemic (from 1st March 2022 to 28th February 2023). The four objectives are: 1) to quantify the rate of fit notes issued before and during the latter part of the COVID-19 pandemic, including in population subgroups; 2) to estimate the independent association between sociodemographic and health-related factors and sickness absence in both periods using multivariable Poisson regression models; 3) to explore the main causes of sickness absence in the working age population in England by using the diagnostic codes recorded at the time of or prior to the date when fit notes were issued; 4) to quantify the economic loss associated with sickness absence. Understanding sickness absence and changing trends over time will offer important insights into the general health and wellbeing of the working-age population, of high relevance to policy makers, employers, insurers, and healthcare planners and providers.
Primary outcome: Medical certificates issued for sickness absence of any cause, referred to throughout the protocol as “fit notes”. These will be defined using SNOMED-CT codes for sickness certification (also known as Statement of Fitness for Work or Med 3 Form). We will be excluding SNOMED-CT codes indicating that an individual may be able to work.
Secondary outcome: Economic loss associated with sickness absence. We will use the IMD income domain data associated with each patient to estimate the cost of their periods of sickness absence.
Shamil Haroon - Chief Investigator - University of Birmingham
Naijie Guan - Corresponding Applicant - University of Birmingham
James Rockey - Collaborator - University of Birmingham
Joht Singh Chandan - Collaborator - University of Birmingham
Krishna Gokhale - Collaborator - University of Birmingham
Krishnarajah Nirantharakumar - Collaborator - University of Birmingham
Louise Jackson - Collaborator - University of Birmingham
Mark Monahan - Collaborator - University of Birmingham
Tom Marshall - Collaborator - University of Birmingham
Tracy Roberts - Collaborator - University of Birmingham
Patient Level Index of Multiple Deprivation Domains