Health researchers have figured out how to identify whether elderly hospital patients are suffering from delirium with nearly complete accuracy in about the same amount of time as it takes to read this paragraph, according to a new study published yesterday in the Journal of Hospital Medicine.

Delirium is a serious problem for elderly patients, who may arrive at the hospital mentally sound only to develop delirium during their stay, possibly from medications or poor sleep, the Philadelphia Inquirer reports.

"Delirium can be very costly and deadly—and with high-risk patients, time matters," Penn State professor Donna Fick says in a press release. Doctors and nurses currently use a 3-minute test to diagnose delirium, but sometimes they don't even have that much time, the researchers note.

That's why Fick developed an "ultra-brief" two-question test for diagnosing delirium that takes an average of 36 seconds to administer and has a 93 percent success rate, according to the press release.

By asking 201 participants—42 of whom were clinically diagnosed with delirium—what day of the week it was and asking them to recite the months of the year backward, researchers were able to identify those with delirium.

The test also incorrectly identified six people with delirium, but Fick says she's fine with false positives, as doctors can use the short test to decide who should get the longer delirium test.

Researchers plan to conduct a larger study of the two-question test before recommending it for use. (Is police brutality just a form of delirium?)

This article originally appeared on Newser: How to Diagnose Delirium in Under 40 Seconds

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