Prevalence of long COVID rises to nearly 7% of population

US government number crunchers published a briefing article in JAMA¹, June 7, 2024, presenting the results of their latest round of analysis on long COVID demographics. Key findings highlighted that women were more likely to disclose that they had had long COVID as were Americans between 35 and 65 years old. White people were more likely to say they had had the condition versus Black, Hispanic and Asian people, with Asian Americans the least likely. Digging into the data, statisticians Zhengyi Fang, MS and Rebecca Ahrnsbrak, MPS further looked into vaccine uptake, household income and medical history to paint a picture of the demographics of individuals suffering from long COVID.  

Prevalence of Long COVID in the US

The researchers estimate that 6.9% of Americans have, or have had long COVID. This startlingly high number was generated from data from the Medical Expenditure Panel Survey (MEPS). The MEPS is a set of surveys funded by the United States federal government to collect data for the Department of Health and Human Services.

This questionnaire gathers information from regular Americans, health care providers and insurance companies to track spending on health conditions. Statisticians use this data to take both a bird’s-eye view of changing trends in diagnosis, treatment preferences and priorities, and create a window into the lives of Americans living with specific conditions.

Using results from the household component of the survey, researchers probed the self-reported circumstances of over 17,000 independently living Americans across the United States. Corresponding to an adult population of 259 million people, these 17,418 adults had a representative mix of income, age, location, education, ethnic and racial heritage allowing the investigators to look at a cross section of American society.

In total 8,275 adults answered that they had had COVID-19 at some point – that’s a whopping 47.5% of Americans over 18. Of these, 1,202 also suffered from long COVID, equating to 6.9% of the US population or nearly 15% of people who had had COVID-19. With the COVID-19 pandemic still grinding on in the background, the number of Americans living with long COVID is set to keep rising.

Canadian COVID-19

What’s more, 2023 Canadian COVID-19 Antibody and Health Survey data gathered by Statistics Canada led Canadian health researchers to conclude that as many as two out of three Canadians have been infected with SARS-COV2. By June 2023 11% of Canadian adults reported that they had experienced lingering symptoms of COVID-19, with 2.1 million saying they were still suffering symptoms.²

Data indicates that repeated COVID-19 infections up the odds that a person will develop long COVID. Statistics Canada estimates that long COVID symptoms have caused 14.5 million missed days or work or school for 600,000+ Canadians.

The differences in data collection, access to health care and cultural attitudes towards illness in the USA versus Canada, could suggest that the prevalence of both COVID-19 infections and long COVID are being under-reported in the USA. Indeed the Nationwide Blood Donor Seroprevalence Survey of US adults conducted by the CDC in 2022 indicated that up to 77% of Americans over the age of 16 have fought off COVID-19 at some point.³

While 17.8 million Americans with long COVID is a huge number, a closer look at the data gives a troubling hint that this is just the tip of the iceberg.

What Lurks Beneath

In the United States most reports of long COVID came from women (8.6%) vs men (5.1%). More than 10% of women between 50 and 64 years old say they have had long COVID, while men tend to report at similar rates across ages.

Long COVID seems to affect people with pre-existing conditions more frequently. Obesity, diabetes, arthritis, heart disease, high blood pressure and high cholesterol increased a person’s likelihood of reporting long COVID. Pre-existing lung disease, such as asthma, chronic bronchitis and emphysema dramatically heightened the risk of lingering symptoms. It is not clear whether the difference between rates in men and women is due to divergent attitudes to health and how often they visit the doctor, or whether females are more clinically vulnerable.

COVID Cautious

Unsurprisingly, people who were able to receive multiple COVID boosters were at lower risk of long COVID with 5.8% reporting lingering symptoms. This was in line with Canadian data indicating that repeated infections increase long COVID likelihood. People who only took part in the first COVID-19 vaccine roll out were slightly more likely to develop long COVID (8.7%) than those who remained unvaccinated. This might reflect a false sense of security evoked by the initial shot that led to people taking fewer precautions against recurrent infections.

Similarly the results indicate that white Americans (around 7%) were more than twice as likely to note long COVID symptoms than Asian Americans (3.3%). Asian Americans were more likely to report having sought out COVID-19 booster shots. Seroprevalence of COVID19 antibodies in 2022 was markedly lower in Asian Americans than other demographics indicating that a more cautious attitude to infection might have been responsible. Black and Hispanic people disclosed long COVID at lower rates than the white population; however, it’s not obvious whether this was due to lack of symptoms or a lack of awareness of long COVID.

Money Matters

Household income and education factored heavily into long COVID reporting. Low household income was associated with lower disclosure of having had COVID-19. This is a concern since seroprevalence studies out of Toronto, Canada, tell the opposite story.⁴ Data collected at COVID assessment centres indicate that low income, high immigration neighbourhoods were hit hardest by COVID-19 in 2022. 

Similarly, the lowest rates of long COVID were reported by low income, low education households. This finding should make us think twice about how we construe the results of this study. As these responses are self-reported from the household component of the survey, it relies heavily on respondent’s access to health care and access to information about long COVID. It will also depend on the individual filling out the poll’s attitudes, how their family culture prioritizes health and subjective approaches to interpreting vague symptoms such as fatigue or brain fog. Both could easily be attributed to the stresses associated with poverty. Under-reporting of long COVID by low income families is a very real possibility.

 
Ticking Time Bomb

As COVID-19 continues to circulate and health authorities increasingly drop surveillance programs, keeping track of the number of people who will develop long COVID is essential. Researchers have not yet learned whether the risk of long COVID changes as the virus that causes COVID-19 mutates. What we do know, however, is that the omicron strain of SARS-COV2 virus added new long COVID symptoms: for example more individuals now report post exertional malaise rather than losing their sense of smell.

Furthermore, repeated infections with COVID19 increase a person’s risk of developing long COVID. Canadian figures tell us that being infected three or more times escalates the risk that an individual will go on to contract long COVID 2.6 fold.

With upwards of 77% of adults having already experienced at least one COVID-19 infection, the number of Americans laid low with long COVID could rise to 40 million or more in the coming years.

References

1. Fang Z, Ahrnsbrak R, Rekito A. Evidence Mounts That About 7% of US Adults Have Had Long COVID. JAMA. Published online June 7, 2024. doi:10.1001/jama.2024.11370 ↩︎
2. Government of Canada SC. Experiences of Canadians with long-term symptoms following COVID-19. Published December 8, 2023. Accessed June 12, 2024. https://www150.statcan.gc.ca/n1/pub/75-006-x/2023001/article/00015-eng.html ↩︎
3. Adjaye-Gbewonyo D, Vahratian A, Cria G. P, Bertolli J. Long COVID in Adults: United States, 2022. National Center for Health Statistics (US); 2023. doi:10.15620/cdc:132417 ↩︎
4. O’Neill B, Kalia S, Hum S, et al. Socioeconomic and immigration status and COVID-19 testing in Toronto, Ontario: retrospective cross-sectional study. BMC Public Health. 2022;22:1067. doi:10.1186/s12889-022-13388-2 ↩︎