Comparative Utility of Barona Formulae, Wtar Demographic Algorithms, and WRAT-3 Reading for Estimating Premorbid Ability in a Diverse Research Sample

Abstract

Various Barona formulae, a WTAR algorithm based on demographic data, and WRAT-3 oral reading methods of estimating premorbid ability were compared in a diverse research sample of 119 subjects. These methods were correlated with one another and with a modified version of the Raven Standard Progressive Matrices. Descriptive data are provided to illustrate advantages and disadvantages of various methods of estimating premorbid ability when no formal intellectual testing is available. While predicting premorbid ability for individual subjects involves varying degrees of error, we found that the revised Barona formula was superior to the original formula for subjects at the upper end of ability level. When researchers have screened out learning disability and have subject samples with few individuals likely to be of superior premorbid intelligence, oral reading scores are a reasonable measure of premorbid ability. Otherwise, researchers are advised to use both demographic and oral reading methods to estimate premorbid ability.

Adjustment of Cognitive Scores with a Co-Normed Estimate of Premorbid Intelligence: Implementation Using Mindstreams Computerized Testing

“…The result is an easy to use clinical tool for improved estimation of premorbid ability and its application in inferring the presence of cognitive impairment. Use of the RPM-like MPST as the ''hold'' test makes the premorbid estimate more widely applicable than Wechsler subtests or reading test measures commonly used (Ball et al, 2007). Indeed, use of a reading test or the WAIS Vocabulary subtest has been criticized for underestimating premorbid IQ as they evidence impairment in a range of conditions (Crawford, 1989;Larrabee, Largen & Levin, 1985;Mathias et al, 2007).…”

“…Indeed RPM is considered among the best measures of g (Llabre, 1984;Jensen, 1998), shows minimal correlation with tests of academic achievement (e.g., Esquivel & Lopez, 1988), and has been employed across cultures and languages (Raven, 2000). RPM shows good correlation (0.6 to 0.7) with the Wechsler scales (O'Leary, 1991;Rijsdijk et al, 2002;Vernon, 1983) and has been used as a standard for evaluating the validity of demographics and word reading premorbid estimates (Ball et al, 2007). Perhaps most importantly for the current study, RPM is highly similar in design and concept to MPST.…”

“…A WAIS-R subtest (e.g., Vocabulary, Information) or a word reading test (e.g., NART, WRAT; see, e.g., Bright et al, 2002;Orne et al, 2004) is often taken as the ''hold'' measure. Use of these ''hold'' measures has been criticized for underestimating or overestimating premorbid IQ (Ball et al, 2007;Crawford, 1989;Griffin et al, 2002;Stebbins et al, 1990a;Wiens et al, 1993;Johnstone et al, 1996) and for inapplicability in patients with significant articulatory or visual acuity problems (Ball et al, 2007;Crawford, 1992; but see Bright et al, 2002).…”

“…However, it explains only a portion of the variance in premorbid IQ, and the equations are typically derived from large random samples, rarely available for neuropsychological tests (Reynolds, 1997). The demographics approach has also been criticized for underestimating or overestimating premorbid IQ (Ball et al, 2007;Basso et al, 2000;Griffin et al, 2002;Veiel & Koopman, 2001).…”

Depression and Neurocognitive Performance in Portuguese Patients Infected with HIV

“…To overcome this difficulty, we decided to perform an intra-individual comparison between the values found in each domain of the neurocognitive battery and the cognitive abilities of their premorbid state [8,[25][26][27] derived from the WAIS-R. The method chosen to accomplish this was first described by Barona et al.…”