The doctor who created the 30-question test for early signs of dementia that Trump famously aced last year says the screening assessment is being misused, according to a report by Kaiser Health News.

Dr. Ziad Nasreddine, the neurologist who wrote the Montreal Cognitive Assessment (MoCA), grew concerned after reviewing hundreds of test results. A closer look at individual patients’ scores suggested that some were wildly off, even calling into question some scores of a perfect 30, like the one Trump earned.

“I’ve seen so much variability, which might make us reconsider some of the decisions made based on the MoCA score,” Nasreddine told KHN. He declined to speculate specifically on Trump’s scoring.

Nasreddine, who owns the copyright to the test, suggests that some doctors administering the exams were not properly following its four-page list of instructions. Starting September 1, Nasreddine will require anyone who administers the test to complete a mandatory $125, one-hour online course. Until now, training has been voluntary.

“The purpose of the training is to make the test more reliable and valid,” he said.

Others were critical of the move, suggesting that it would create a “pay to play” scenario. “It raises huge red flags,” according to geriatrician Dr. Eric Widera, of the University of California-San Francisco. “This is a growing issue, the monetization of tools that we promoted as the standard.”

The MoCA was created by Nasreddine in 1996 and has become a widely used screening tool for early signs of dementia. It’s used all over the world, and in the US, it is given thousands of times a year in federally funded Alzheimer’s research centers.

It quickly assesses cognitive abilities such as short-term memory recall, language use, attention, and visuospatial and executive functions. Test takers are asked to complete seemingly simple tasks such as identifying animals, drawing the time on a clock face, calculating basic math problems, remembering the order of a list of numbers, and naming as many words as possible that start with the letter F in under a minute.

A score of 26 or higher is considered normal, with 18 to 25 indicating mild impairment, ten to 17 suggesting moderate impairment, and less than ten pointing to severe impairment. Patients with scores indicating impairment should move on to more detailed evaluations.

Though MoCA has been in use for years, the handy test was thrust into the limelight last year when Donald Trump’s then-physician, Dr. Ronny Jackson, administered the test during the president’s annual physical and announced that Trump had scored a perfect 30 points.

Since then, Nasreddine says he has noticed a worrying number of unexplained variations in individual patients’ scores—for example, differences of five points in test scores in the same patient obtained just weeks apart, which can’t be explained by disease progression. He also noted cases in which patients lost jobs or were stripped of legal rights based on low MoCA results that were scored by untrained medical providers.