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Abstracts
Clin Neuropsychol 2000
Aug;14(3):325-40
Limited accuracy of premorbid intelligence
estimators: a demonstration of regression to the mean.
Basso MR, Bornstein RA, Roper BL, McCoy VL.
Department of Psychology, University of Tulsa, OK
74104-3189, USA. michael-basso@utulsa.edu
Regression-based premorbid intelligence estimators have
been devised by Barona, Reynolds, and Chastain (1984),
Barona and Chastain (1986), Hamsher (1984), Krull,
Scott, and Sherer (1995; the Oklahoma Premorbid
Intelligence Estimate: OPIE), and Vanderploeg, Schinka,
and Axelrod (1996; BEST-3 approach), but little is known
of their relative accuracy, particularly in outer ranges
of intellectual ability (e.g., below-average, superior,
etc.). Towards this end, the Wechsler Adult Intelligence
Scale-Revised (WAIS-R) was administered to 150
neurologically normal adults, and estimated VIQ, PIQ,
and FSIQ scores were computed according to each
regression method. Results showed that methods based
solely on demographic factors were most susceptible to
meanward regression, rendering them poor estimators of
IQ scores in outer ranges. Although the OPIE and BEST-3
performed somewhat better, their accuracy remained
relatively weak. The findings suggest that
regression-based estimates of premorbid IQ are very
susceptible to error, particularly in outer ranges of
intellectual function.
J Clin Exp Neuropsychol
1999 Jun;21(3):368-74
WAIS-R prediction equations in patients with
traumatic brain injury.
Axelrod BN, Vanderploeg RD, Rawlings DB.
John D. Dingell Department of Veterans Affairs Medical
Center, Detroit, MI, USA. axelrod.bradley@forum.va.gov
Arithmetic algorithms for predicting premorbid Full
Scale IQ were evaluated in a sample of 125 brain injured
adults who had been evaluated within two months of their
injury, and then again one year later. FSIQ at post-test
was used as the criterion variable. The prediction
equation, based on demographic information only (Barona,
Chastain, & Reynolds, 1984), proved to be a modest
predictor of premorbid FSIQ. The BEST-3 (Vanderploeg &
Schinka, 1995), a prediction equation that incorporates
demographic information and performance data, was
sensitive to the severity of the brain injury.
Subsequent analyses found the BEST-3 to be a better
predictor of recovery of function than it was an
estimate of premorbid functioning. This study
demonstrates the need for flexibility in the
interpretation of results, as what was thought to be a
prediction equation for premorbid functioning was better
viewed as an estimate of recovery.
J Clin Psychol 1997
Nov;53(7):647-56
Estimating premorbid WAIS-R intelligence in the
elderly: an extension and cross validation of new
regression equations.
Paolo AM, Ryan JJ, Troster AI.
University of Kansas Medical Center, Kansas City 66160,
USA.
Recently developed equations that combine WAIS-R
subtests and demographic information to estimate
premorbid intelligence were evaluated in persons 75
years and older. The equations underestimated the
obtained IQs of elderly persons. Therefore, new
equations were developed using the old age WAIS-R
standardization sample. The new equations
cross-validated well and demonstrated adequate ability
to detect possible intellectual deterioration in a brain
damaged sample. The demographic formulas of Barona,
Reynolds, and Chastain worked as well as the new
equations in suggesting possible deterioration in a
sample of elderly persons with chronic and diffuse
cognitive impairment.
J Clin Psychol 1996
May;52(3):335-43
Utility of the Barona demographic equations to
estimate premorbid intelligence: information from the
WAIS-R standardization sample.
Paolo AM, Ryan JJ, Troster AI, Hilmer CD.
Department of Neurology, University of Kansas Medical
Center, Kansas City 66160-7314, USA.
The WAIS-R (Wechsler, 1981) and elderly WAIS-R
standardization samples (Ryan, Paolo, & Brungardt, 1990)
were combined to evaluate the utility of the Barona
demographic regression equations (Barona, Reynolds, &
Chastain, 1984) to estimate premorbid intelligence. The
equations underestimated ability for persons with IQs
less than 80 and overestimated ability of subjects with
IQs greater than 119. The equations also overestimated
the IQs of 247 persons with confirmed brain dysfunction.
Because this overestimation occurred for impaired
persons with IQs less than 90, it is difficult to
determine whether the difference reflects true
intellectual deterioration or statistical artifact.
Abnormal cut-off scores at the 10% and 5% levels are
provided to allow clinicians to detect abnormal
discrepancies between the estimated and obtained IQs.
The Clinical
Neuropsychologists 2000 14(2):181-186
PPVT-R as an Estimate of Premorbid Intelligence in
Older Adults.
Snitz BA, Bieliauskas LA,
Crossland A, Basso MR, Roper B.
The Peabody Picture
Vocabulary Test-Revised (PPVT-R) was examined as an
estimate of premorbid intelligence in a clinical sample
of elderly patients (N = 150) undergoing clinical
neuropsychological evaluation. PPVT-R standard scores
were compared across grossly cognitively intact,
mildly/moderately and severely impaired groups of
patients, and compared to a short form of the Wechsler
Adult Intelligence Scale-Revised (WAIS-R) and the Barona
regression equation. Results indicate that, while the
PPVT-R is vulnerable to increasing levels of cognitive
impairment among patients with fewer years of education,
the PPVT-R is stable across mild to moderate levels of
impairment for patients with greater than 12 years of
education. In a sub-sample of grossly cognitively intact
patients (n = 91), the PPVT-R standard score correlated
significantly with estimated WAIS-R FSIQ (r = .61).
Compared to the Barona equation, the PPVT-R was less
likely to over-estimate WAIS-R FSIQ in the grossly
cognitively intact patients. These data suggest the
PPVT-R to be a useful estimate of premorbid ability for
patients with a greater than high-school education.
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