Prior morbidity and sickness absence with Covid-19 among wholesale and retail blue-collar workers

BACKGROUND: Cancer, cardiovascular disease, hypertension, diabetes, chronic kidney disorders, chronic lung disorders, neurological disorders, obesity, immunocompromisation, and schizophrenia or bipolar disorders were found to be risk factors for severe Covid-19. The aim was to determine associations between having such diagnoses and future sickness absence (SA) due to Covid-19 or related diagnoses in 2020. METHODS: A prospective population-based cohort study of all 299,268 blue-collar workers (48% women) in Sweden in 2018, using linked microdata from four nationwide registers covering 2018-2020. People with any of the above diagnoses in 2018 or 2019 were identified using microdata from specialised in- and outpatient healthcare and prescribed drugs. Logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (CI) of a new SA spell >14 days due to diagnosed Covid-19 or one of the diagnoses used by the Social Insurance Agency for suspected Covid-19 in 2020, separately for each diagnosis group and a global estimate for all risk factors together, adjusted for sociodemographic characteristics. RESULTS: In total, 38,422 individuals had at least one of the diagnoses that was a risk factor for severe Covid-19. Of them, 284 individuals had SA due to Covid-19 or related diagnoses (0.7%) in 2020, while 1210 of those with no such risk factor for Covid-19 had SA due to Covid-19 or related diagnoses (0.5%). The adjusted OR of SA due to Covid-19 or related diagnoses was 1.37 (95% CI 1.20-1.56) for those who had any risk factors for severe Covid-19. The group of diagnoses with the highest adjusted OR for SA in Covid-19-related diagnoses was lung disease (2.23; 95% CI 1.93-2.56). CONCLUSIONS: While only a few of those with prior morbidity that was a risk factor for severe Covid-19 had SA due to Covid-19 or related diagnoses in 2020, they had a higher risk than those without such prior morbidity. KEY MESSAGES: • Having prior morbidity with a diagnosis identified as a risk factor for severe Covid-19 was associated with a higher risk of having SA due to Covid-19 or related diagnoses in 2020. • Prior lung disease was the diagnosis group with the highest risk of SA due to Covid-19 or related diagnoses.