Am J Psychiatry 1984; 141:663-667
Copyright © 1984 by American Psychiatric Association
Failure of nonlinear models of drinking history variables to predict neuropsychological performance in alcoholics
KM Adams and I Grant
To test whether the relationship between drinking parameters and cognitive
functioning can be visualized as a curvilinear surface (rather than as a
line, which more traditional regression equations presuppose), the authors
tested 84 recently detoxified and 72 longer- term abstinent alcoholic men
with the Halstead-Reitan battery. Quadratic statistical models did not
predict test performance in the first group; a few predictions were found
in the second. When the multiple correlation was adjusted for number of
cases and variables, the "nonlinear" results were statistically no more
significant than those of simpler linear models. It is concluded that
drinking history does not readily explain cognitive findings among sober
alcoholics and that polynomial models can produce inflated correlation
coefficients.
