CDR is calculated on the basis of testing six different cognitive and behavioral domains such as memory, orientation, judgment and problem solving, community affairs, home and hobbies performance, and personal care. The CDR is based on a scale of 0-3: no dementia (CDR = 0), questionable dementia (CDR = 0.5), MCI (CDR = 1), moderate cognitive impairment (CDR = 2), and severe cognitive impairment (CDR = 3). The six domains are often summed to create a 0 - 18 "sum of the boxes" score. CDR-SB has been shown to demonstrate sensitivity to cognitive changes associated with progression of amnestic mild cognitive impairment (aMCI) and early Alzheimer's Disease (AD).