Higher levels of long COVID were found in lower-income households.
One child aged 17 or under was randomly selected from each sample household within the survey, and parents responded to questions about whether their child had previous COVID-19 illness, if the child had symptoms lasting three months or longer and if the child still had those symptoms at the time of interview.
Results of the analysis, published in the journal JAMA Pediatrics, showed approximately 1.01 million children, or 1.4%, are believed to have ever experienced long COVID as of 2023 and about 293,000, or 0.4%, were experiencing the condition when the survey was being conducted.
This is similar to the 1.3%, or about 1 million, of children ever estimated to have had long COVID as of 2022, according to the authors.

Among children currently experiencing long COVID at the time of interview, 80% reported to have some level of activity limitation compared with before they had COVID-19.
"The large proportion of children experiencing [long COVID] with any activity limitation highlights the need to examine the severity of activity limitation, functional outcomes, and days lost from school," the authors wrote.
The authors said there may be an under-reporting of long COVID in younger children due to difficulty with the verbalization of their symptoms.
