The website and materials I've found claim that this is an adaptive test, so that it's not testing a 5th grader on 5th grade material but rather starts at lower levels and moves higher until the kid misses a lot. They do claim that the grade level means a kid has mastered a given grade level material. The test is so fast and so quick-and-dirty that I'm not sure the results should be taken too seriously.
My son's school uses these tests, but I don't think they are complete enough or accurate enough to give much guidance.
