Nearly 1 in 7 working-age US adults had experienced long COVID by late 2023, and socially disadvantaged adults were over 150% more likely to have persistent symptoms, two new studies find.
Future public health, economic burdens
Yesterday in Communications Medicine, Daniel Kim, MD, DrPH, of Northeastern University, analyzed data from the US Census Bureau's Household Pulse Survey from September and November 2022 and August to October 2023 on more than 375,000 US adults, including nearly 50,000 with self-reported long COVID.
Kim assessed sociodemographic and socioeconomic factors as predictors of long COVID; estimated the risk of unemployment, financial difficulties, and anxiety and depression among working-age adults (ages 18 to 64 years) and those currently experiencing lingering symptoms; and tallied the economic effects of the resulting lost wages.
"In the United States, concerns have been increasingly raised over the future public health and economic burden of long COVID including disability and declines in labor force participation," he wrote. "However, only a handful of U.S. studies have explored sociodemographic or socioeconomic characteristics that put people at risk of long COVID or have investigated its economic and mental health sequelae."
Large-scale government funding needed
About 35 million adults and 30 million working-age adults, or roughly 1 in 7, said they had experienced long COVID by late 2022 and 2023. Lost wages due to long COVID among working-age survey respondents were estimated at $211 billion in 2022 and $218 billion in 2023.
An age- and sex-adjusted model of 2022 data from 154,430 participants estimated that those vaccinated against COVID-19 had a 14% lower risk of protracted symptoms than their unvaccinated peers, but a fully adjusted model found no difference in risk. In comparison, a fully adjusted model of 2023 data from 220,664 respondents found a higher risk of long COVID among the vaccinated than the unvaccinated.
Risk factors for the condition were lower household income, Hispanic ethnicity, female sex, and gay, lesbian, or bisexual status. Long COVID was tied to elevated risks of recent unemployment, financial problems, and anxiety and depression.
Roughly 14.5 million adults overall and 10.9 million adults with long COVID still had symptoms in fall 2022 and fall 2023, respectively. Among adults with current long-COVID symptoms, there was evidence of a dose-response relationship, with those reporting the most impact on daily functioning having a more than two-fold higher risk of recent depression than those reporting no impact.
"Overall, an estimated 24 million working-aged adults with long COVID had been or may still be at risk of adverse socioeconomic and mental health outcomes," Kim concluded. "The scale of long COVID and its sequelae necessitates large-scale governmental funding to address long COVID research priorities and a robust and coordinated policy response strategy, as well as ongoing national surveillance of the prevalence and health and economic burden of long COVID."
Women, Black participants most affected
A survey-based report this week in BMC Medicine by Anhui Medical University researchers in China highlights the relationship between adverse social determinants of health (SDoH) and long COVID in the United States.
Black communities are often concentrated in areas with limited healthcare access, environmental pollution, and food insecurity, factors all linked to chronic inflammation and impaired recovery.
The investigators parsed data on 16,446 US adults with a history of COVID-19 infection, 3,111 (18.6%) of them with long COVID, from the 2022 and 2023 National Health Interview Surveys from the National Center for Health Statistics. They measured cumulative social disadvantage using 18 SDoH indicators categorized into quartiles. The average participant age was 48.1 years.
"Although the influence of SDoH on health conditions is well established, its relationship with long COVID has yet to be sufficiently explored," they wrote. "Understanding the relationship between cumulative social disadvantage and long COVID is crucial for identifying vulnerable populations and offering more tailored management and support."
Respondents in the highest quartile of social disadvantage were 152% more likely to report long COVID than those in the lowest quartile (adjusted odds ratio [aOR], 2.52). This link persisted across demographic subgroups, with greater effects on women and Black participants and, to a lesser extent, Hispanic and White adults.
"The stronger association among non-Hispanic Black groups reflects systemic inequalities beyond socioeconomic status," the researchers wrote. "Black communities are often concentrated in areas with limited healthcare access, environmental pollution, and food insecurity, factors all linked to chronic inflammation and impaired recovery."
Role of occupational exposure, discrimination
The greatest social disadvantage burden was seen more often among long-COVID patients than among those without the condition (29.2% vs 15.2%). Adults with protracted symptoms in the most disadvantaged group were more than six times more likely to report poor general health than those in the least disadvantaged group (aOR, 6.34). Risk factors for long COVID included mental illness, financial instability, and poor healthcare access.
Addressing systemic inequities through integrated public health strategies is essential to mitigate the burden of long COVID and reduce social disparities in health.
The authors noted that social disadvantage prolongs COVID-19 symptoms by amplifying oxidative stress and immune dysregulation and that disadvantaged groups are more likely to engage in harmful behaviors, which increases their susceptibility to chronic conditions.
"Beyond poverty, social inequalities such as occupational exposure and racial discrimination also make certain populations more vulnerable to virus exposure," they wrote. "Workers in long-term care facilities and public service sectors, including education, social care, and transportation, are at higher risk for long COVID."
The researchers said that healthcare providers need to take a holistic approach, particularly with socially disadvantaged groups during post-COVID recovery, by incorporating systematic screening for SDoH to identify high-risk populations and offer timely interventions.
"Addressing systemic inequities through integrated public health strategies is essential to mitigate the burden of long COVID and reduce social disparities in health," they wrote.
