Rk. Heaton et al., Detecting change: A comparison of three neuropsychological methods, using normal and clinical samples, ARCH CLIN N, 16(1), 2001, pp. 75-91
Detecting change in individual patients is an important goal of neuropsycho
logical testing. However, limited information is available about test-retes
t changes, and well-validated prediction methods are lacking. Using a large
nonclinical subject group (N=384), we recently investigated test-retest re
liabilities and practice effects on the Wechsler Adult Intelligence Scale a
nd Halstead-Reitan Battery. Data from this group also were used to develop
models for predicting follow-up test scores and establish confidence interv
als around them. In this article we review those findings, examine their ge
neralizability to new nonclinical and clinical groups, and explore the sens
itivity of the prediction models to real change. Despite similarities acros
s samples in reliability coefficients and practice effects, limits to the g
eneralizability of prediction methods were found. Also, when multiple test
measures were considered together, one or more "significant" changes were c
ommon in all (including stable) subject groups. By employing normative cut-
offs that correct for this, sensitivity of the models to neurological recov
ery and deterioration was modest to good. More complex regression models we
re not more accurate than the simpler Reliable Change Index with correction
for practice effects when confidence intervals for all methods were adjust
ed for variations in level of baseline test performance. (C) 2000 National
Academy of Neuropsychology. Published by Elsevier Science Ltd.