Serial sevens: not the most effective test of mental status in high school athletes

To evaluate the ability of uninjured high school athletes to pass three mental status tests that are commonly used on the sidelines for the evaluation of concussions: the serial sevens test, the serial threes test, and recitation of months of year in reverse order (MOYR).

High school student athletes in grades 9, 10, 11, and 12 having sports preparticipation physical examinations. The initial study tested 522 consecutive athletes. The follow-up study tested 109 consecutive athletes.

The athletes of the initial group were asked to perform a serial sevens test, followed by a serial threes test, and finally to recite the MOYR. The second group was asked to perform the same tests in a random order.

Participants were given 1-min time limits for each test, with passing defined as either 7 consecutive correct iterations or 11 correct with one mistake.

For the initial group, 51.3% successfully performed serial sevens, 78.7% successfully performed serial threes, and 89.5% successfully recited the MOYR. For the second group, 52.7% successfully performed serial sevens, 78.1% successfully performed serial threes, and 88.9% successfully recited the MOYR. The pass rates were significantly different for both groups. The pass rates were similar for both sexes, all grade levels, and all sports in both test groups. Participants, both overall and in all subgroups, failed serial sevens more often than serial threes and MOYR (p < 0.001 for the initial group; p < 0.0001 for the second group). They failed serial threes more often than MOYR (p < 0.001 for the initial group; p < 0.01 for the second group).

The percentage of uninjured high school athletes successfully completing serial sevens is too low to make the test useful for evaluation of concussion; the test lacks specificity. The percentage of athletes passing the MOYR was greatest, perhaps making this a better sideline test than the traditional serial sevens test. However, testing needs to be done in injured athletes before clinical application can be recommended.