Fit notes associated with COVID-19 in 24 million patients’ primary care records

This study quantified the fit note rate in people with documented SARS-CoV-2 infection or COVID-19 diagnosis in 2020, 2021 and 2022 overall, by demographics, and by time since diagnosis. We also used adjusted Cox regression to compare the fit note rate to the general population.

Paper information

Authors: Andrea Schaffer,

Robin Park,

John Tazare,

Krishnan Bhaskaran,

Brian MacKenna,

Spiros Denaxas,

Iain Dillingham,

Seb Bacon,

Amir Mehrkar,

Chris Bates,

Ben Goldacre,

Felix Greaves,

John Macleod,

Laurie Tomlinson,

Alex Walker
Citation: Schaffer AL, Park RY, Tazare J, et al. Fit notes associated with COVID-19 in 24 million patients’ primary care records: A cohort study in OpenSAFELY-TPP. medRxiv 2023.07.28.23293269v1; doi: https://doi.org/10.1101/2023.07.28.23293269
DOI: 10.1101/2023.07.28.23293269
Categories: OpenSAFELY

Abstract

Background

Fit notes (“sick notes”) are issued by general practitioners (GPs) when a person can’t work for health reasons and is an indication of the public health and economic burden for people recovering from COVID-19.

Method

With NHS England approval, we used routine clinical data from >24 million patients to compare fit note incidence in people 18-64 years with and without evidence of COVID-19 in 2020, 2021 and 2022. We fit Cox regression models to estimate adjusted hazard ratios, overall and by time post-diagnosis and within demographic subgroups.

Results

We identified 365,421, 1,206,555 and 1,321,313 people with evidence of COVID-19 in 2020, 2021 and 2022. The fit note rate was 4.88 per 100 person-months (95%CI 4.83-4.93) in 2020, 2.66 (95%CI 2.64-2.67) in 2021, and 1.73 (95%CI 1.72-1.73) in 2022. Compared with the age, sex and region matched general population, the hazard ratio (HR) adjusted for demographics and clinical characteristics over the follow-up period was 4.07 (95%CI 4.02-4.12) in 2020 decreasing to 1.57 (95%CI 1.56-1.58) in 2022. The HR was highest in the first 30 days post-diagnosis in all years.

Conclusion

Despite likely underestimation of the fit note rate, we identified a considerable increase among people with COVID-19, even in an era when most people are vaccinated. Most fit notes are associated with the acute phase of the disease, but the increased risk several months post-diagnosis provides further evidence of the long-term impact.