Exploring predictors of post-COVID-19 condition among 810 851 individuals in Sweden

TL;DR

This study identifies risk factors for long-term post-COVID-19 condition in a large Swedish population to help prevent future cases.

Contribution

The study provides a comprehensive analysis of multiple risk factors for post-COVID-19 condition using a large national dataset.

Findings

Female sex, older age, and being born outside Sweden are associated with increased PCC risk.

Comorbidities like asthma and depression, as well as not being vaccinated, are linked to higher PCC risk.

Having a relative or cohabitant with PCC also increases the likelihood of being diagnosed with PCC.

Abstract

Long-term effects of COVID-19 can place burden on individuals, healthcare, and society. We aimed to evaluate the importance of a wide range of potential risk factors for being diagnosed with post-COVID-19 condition (PCC).

We used data from national and regional registers and databases for all adult residents in the two largest regions in Sweden. Individuals with a first COVID-19 between 1 August 2020 and 9 February 2022 were included and followed until PCC diagnosis, censoring (death or migration), or 30 November 2023. Using Cox proportional hazards models and backwards stepwise selection, we evaluated a large set of risk factors including sociodemographic data, comorbidities, healthcare contact behaviors, COVID-19-related factors, as well as PCC in family and cohabitants (as proxies for genetics and shared environment).

We include 810,851 individuals (age range 18-106 years and 53.3% women), of whom 1.4% are diagnosed with PCC during follow-up. Female sex, older age, being born outside Sweden, higher educational attainment, essential workers, having comorbidities such as thromboembolic disease, asthma, fibromyalgia, depression/anxiety, and stress-related disorders, being infected earlier in the study period, experiencing severe acute COVID-19, not being vaccinated before COVID-19, and having a relative or a cohabitant with PCC are associated with an increased risk of being diagnosed with PCC.

In this large population-based cohort study, our exploratory analysis reveals several risk factors for being diagnosed with PCC. Our findings can serve as a basis for future targeting of preventive measures against PCC.

Long-term effects of COVID-19 can place burden on individuals, healthcare, and society. We aimed to explore a wide range of potential risk factors for being diagnosed with post-COVID-19 condition (PCC). We included 810,851 individuals, of whom 1.4% were diagnosed with PCC during follow-up, using data from registers in Sweden. Female sex, older age, being born outside Sweden, higher educational attainment, essential workers, having comorbidities such as thromboembolic disease, asthma, fibromyalgia, depression/anxiety, and stress-related disorders, being infected earlier in the study period, experiencing severe acute COVID-19, not being vaccinated before COVID-19, and having a relative or a cohabitant with PCC are associated with an increased risk of being diagnosed with PCC. Our findings can serve as a basis for future targeting of preventive measures against PCC.

Xu et al. explore predictors of post-COVID-19 condition (PCC) among 810,851 individuals in Sweden using register data. The results reveal several risk factors for being diagnosed with PCC that can serve as a basis for future targeting of preventive measures against PCC.

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