Validity of regression-based norms: an empirical test of the comprehensive norms with older adults

This study empirically tested Fastenau and Adams' (1996) concerns about using regression-based norms (RBN) to statistically correct for demographic influences. A widely used RBN system (Heaton, Grant, & Matthews, 1991) was applied to scores from 63 healthy older adults for the Trail Making Test, Boston Naming Test, and Wisconsin Card Sorting Test (WCST). Age influences on all tests were virtually eliminated by the RBNs, whereas education influences were created by the RBN (better educated older adults penalized by the norms). Using RBNs from the Revised WCST Manual also created distortions, far overcorrecting for age. These findings cast considerable suspicion on norms that are generated by statistical regression when there are not adequate numbers of people supporting each demographic cell. Clinically, these norms can lead to higher rates of false negatives (or missed diagnoses) in older adults, especially those with less education and especially women in their 60s.