Modeling the relative influence of socio-demographic variables on post-acute COVID-19 quality of life
Authors: Menkir Tigist F. , Citarella Barbara Wanjiru , Sigfrid Louise , Doshi Yash , Reyes Luis Felipe , Calvache Jose A. , Kildal Anders Benjamin , Nygaard Anders B. , Holter Jan Cato , Panda Prasan Kumar , Jassat Waasila , Merson Laura , Donnelly Christl A. , Santillana Mauricio , Buckee Caroline , Verguet Stéphane , Hejazi Nima S. ,   The ISARIC Clinical Characterisation Group
Published: July 2024

Importance

Post-acute sequelae of SARS-CoV-2, referred to as “long COVID”, are a globally pervasive threat. While their many clinical determinants are commonly considered, their plausible social correlates are often overlooked.

Objective

To compare social and clinical predictors of differences in quality of life (QoL) with long COVID. Additionally, to measure how much adjusted associations between social factors and long COVID-associated quality of life are unexplained by important clinical intermediates.

Design, Setting, and Participants

Data from the ISARIC long COVID multi-country prospective cohort study. Subjects from Norway, the United Kingdom (UK), and Russia, aged 16 and above, with confirmed acute SARS-CoV-2 infection reporting >= 1 long COVID-associated symptoms 1+ month following infection.

Exposure

The social exposures considered were educational attainment (Norway), employment status (UK and Russia), and female vs male sex (all countries).

Main outcome and measures

Quality of life-adjusted days, or QALDs, with long COVID.

Results

This cohort study included a total of 3891 participants. In all three countries, educational attainment, employment status, and female sex were important predictors of long COVID QALDs. Furthermore, a majority of the estimated relationships between each of these social correlates and long COVID QALDs could not be attributed to key long COVID-predicting comorbidities. In Norway, 90% (95% CI: 77%, 100%) of the adjusted association between the top two quintiles of educational attainment and long COVID QALDs was not explained by clinical intermediates. The same was true for 86% (73%, 100%) and 93% (80%,100%) of the adjusted associations between full-time employment and long COVID QALDs in the United Kingdom (UK) and Russia. Additionally, 77% (46%,100%) and 73% (52%, 94%) of the adjusted associations between female sex and long COVID QALDs in Norway and the UK were unexplained by the clinical mediators.

Conclusions and Relevance

This study highlights the role of socio-economic status indicators and female sex, in line with or beyond commonly cited clinical conditions, as predictors of long COVID-associated QoL, and further reveal that other (non-clinical) mechanisms likely drive their observed relationships. Our findings point to the importance of COVID interventions which go further than an exclusive focus on comorbidity management in order to help redress inequalities in experiences with this chronic disease.

Key Points

Question

How do social and medical factors compare in predicting differences in quality of life (QoL) with long COVID and to what extent do clinical mediators explain social variables’ relationships with long COVID QoL?

Findings

Socio-economic proxies employment status and educational attainment and female sex ranked on par with or above age and neuropsychological and rheumatological comorbidities as predictors of variation in long COVID QoL across participants. Additionally, estimated adjusted associations between each of these social factors and long COVID QoL were largely unexplained by a set of key comorbidities.

Meaning

Long COVID-based interventions may be more broadly beneficial if they account for social disparities as important risk factors for differential long COVID burden and, in addition to clinical targets, address broader structural determinants of health.