May 11, 2018Baseline Caution
Baseline tests are thought to be a crucial tool in the fight for better concussion management, as they are meant to provide a comparison point for pre- and post-head injury function. However, a recently published review of data suggests that baseline testing often gives invalid results. The review examined tests from nearly 7,900 athletes whose ages ranged from 10 to 21.
An article from MDLinx reports that in examining the data, Christopher Abeare, PhD, Associate Professor in Psychology at the University of Windsor in Ontario, and colleagues found high levels of variability in baseline tests. The validity was influenced by the athlete’s age and the indicator that was used, with the rate of failure going from 29.2 percent for 21-year-olds up to 83.6 percent for 10-year-olds. For the four published Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) validity indicators, the failure rates ranged from 6.4 percent to 47.6 percent.
“The one that’s included in the ImPACT was the least sensitive of all the four,” Dr. Abeare told Reuters Health. “We and others think that it’s not the best metric to look at performance validity. Those other three seem to be better.”
There are a number of factors that may influence baseline test results. This could involve an athlete having an off day or other test-related elements—such as taking the test in a large group—interfering with the athlete’s performance.
“These computer tests, they have to be carefully proctored, and they really shouldn’t be done in large groups, especially in kids, because the kids will be inattentive, and I think that’s what a lot of these results show,” said Munro Cullum, PhD, ABPP/ABCN, Chief of Neuropsychology and Professor of Psychiatry, Neurology, and Neurotherapeutics at the University of Texas Southwestern Medical Center, who was not involved in the study. “There are many, many factors that can influence computer test performance. You can’t just look at the validity indicators that the ImPACT test provides, you actually have to have appropriate training and a background in psychology in order to interpret the results that the computer program puts out.”
Although baseline testing is increasing in frequency, Dr. Abeare suggests that caution should be exercised in using them. If an athlete’s baseline level is not measured accurately, the return-to-play decision could be made too soon in the recovery process.
“Although baseline testing can be quite useful in the context of sports-related concussions, this potential usefulness can be dramatically undermined when athletes are not performing on their best on that test day,” said Dr. Abeare.
“At this point in the state of our knowledge, we recommend a conservative approach because there are young athletes’ brains at stake here,” he continued. “We are recommending looking at all four of these validity indicators and even if one is failed, the clinician should really take that into consideration in making decisions about when to return them to play.”