Mo' money, mo' sleep.

That's the takeaway from a fascinating slice of data from the Centers for Disease Control and Prevention looking at sleep levels by income group. Crunching numbers from the 2013 National Health Interview Survey, CDC researchers found that the relationship between income and sleep is linear and positive.

Just less than two-thirds of people living below the federal poverty line — $23,550 for a family of four in 2013 — reported getting more than 6 hours of sleep per night that year. But nearly three-quarters of people with incomes at 400 percent of the poverty level — $94,200 for that same family of four — reported getting that much sleep.

The CDC has called sleep deficiency a "public health epidemic," and with good reason: "Persons experiencing sleep insufficiency are also more likely to suffer from chronic diseases such as hypertension, diabetes, depression and obesity, as well as from cancer, increased mortality, and reduced quality of life and productivity," the centers wrote last year.

The data illustrate how these burdens — like so many of our public health problems — fall disproportionately on the poor. One reason lower-income Americans aren't sleeping as much? Many of them are holding down multiple jobs to make ends meet.

Washington Post