We are seeing a similar effect across all socioeconomic backgrounds. Or at least locally here, Hospital admissions for Winter 2023-2024 almost hit another all time high (nearly hitting the same numbers as peak COVID) - https://www.mlive.com/public-interest/2024/01/covid-on-the-r...

I think we are seeing a similar spike across all backgrounds - other news stories in this press cycle have highlighted that one thing unusual about this surge in absences is that it's affecting affluent and poor districts alike, and that well-off kids are missing school too.

Anecdotally that seems to be the case in my kids' school district (although one complicating factor is that a lot of kids have family back in India or China and go back for long absences at winter break), and the culprit is generally illnesses, which have been extremely rough the past 2 winters.

Richer kids get more vitamins and high quality food in general, have more exercise, have good winter clothing, clean and warm bed sheets, their home isn't full of mold and other problems, their water might be higher quality...

The local hospitals in my community have been full of hospitalized kids with different respiratory issues this winter. My doctor commented that this is a post-pandemic effect.