Development of the Korean Adult Reading Test (KART) to estimate premorbid intelligence in dementia patients

Abstract

We aimed to develop a word-reading test for Korean-speaking adults using irregularly pronounced words that would be useful for estimation of premorbid intelligence. A linguist who specialized in Korean phonology selected 94 words that have irregular relationship between orthography and phonology. Sixty cognitively normal elderly (CN) and 31 patients with Alzheimer’s disease (AD) were asked to read out loud the words and were administered the Wechsler Adult Intelligence Scale, 4th edition, Korean version (K-WAIS-IV). Among the 94 words, 50 words that did not show a significant difference between the CN and the AD group were selected and constituted the KART. Using the 30 CN calculation group (CNc), a linear regression equation was obtained in which the observed full-scale IQ (FSIQ) was regressed on the reading errors of the KART, where education was included as an additional variable. When the regressed equation computed from the CNc was applied to 30 CN individuals of the validation group (CNv), the predicted FSIQ adequately fit the observed FSIQ (R2 = 0.63). In addition, independent sample t-test showed that the KART-predicted IQs were not significantly different between the CNv and AD groups, whereas the performance of the AD group was significantly worse in the observed IQs. In addition, an extended validation of the KART was performed with a separate sample consisted of 84 CN, 56 elderly with mild cognitive impairment (MCI), and 43 AD patients who were administered comprehensive neuropsychological assessments in addition to the KART. When the equation obtained from the CNc was applied to the extended validation sample, the KART-predicted IQs of the AD, MCI and the CN groups did not significantly differ, whereas their current global cognition scores significantly differed between the groups. In conclusion, the results support the validity of KART-predicted IQ as an index of premorbid IQ in individuals with AD.

Cognitive reserve proxies, Alzheimer pathologies, and cognition

“…Formal education was defined as “education which takes place in education and training institutions, leading to recognized diplomas or qualifications” ( Commission of the European Communities, 2000 ). pIQ was estimated by the performance on the Korean Adult Reading Test ( Yi et al, 2017 ), a word-reading test for Korean-speaking adults using 50 irregularly pronounced words that is useful for estimating premorbid intelligence. The Korean Adult Reading Test-predicted Full-Scale IQ, derived from the Korean Adult Reading Test error score, was used as the pIQ of an individual.…”

Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease: Methodology and Baseline Sample Characteristics

“…The full battery consisted of the Mini-Mental State Examination in the Korean version of the CERAD assessment packet (MMSE-KC), 29 CERAD-K verbal memory tests, 29 including Word List Memory, Word List Delayed Recall, Word List Recognition, CERAD-K Constructional Praxis, 29 and CERAD-K nonverbal memory delayed recall, 29 the Trail Making Test A and B, 45 and the Stroop Test (Korean Golden version), 46 Verbal Fluency Tasks (both semantic 29 and phonemic 47 ), CERAD-K confrontational naming test (Modified Korean version of the Boston Naming Test), 29 Wechsler Adult Intelligence Scale-revised edition Korean version (WAIS-R-K) Digit Span (forward and backward), 48 49 Wechsler Memory Scale-Fourth edition Korean version (WMS-IV-K) Logical Memory I, II and Recognition (both stories), 50 Rey Complex Figure Test (RCFT), 51 and the Wechsler Adult Intelligence Scale-Fourth edition Korean version (WAIS-IV-K) Block Design. 52 The length of the full assessment was -2 h. All participants were also administered the Korean Adult Reading Test (KART) 53 to estimate premorbid functioning.…”

Resting State Glucose Utilization and Adult Reading Test Performance

“…The KART, the validated Korean version of ART, was administered to all participants (Yi et al, 2017). KART-estimated Wechsler Adult Intelligence Scale, 4th edition (K-WAIS-IV) full-scale IQ (FSIQ) was used as a measure for ART performance.…”

“…The most widely applied approach to estimating premorbid cognitive function is the use of an adult reading test (ART), which comprises of oral reading of orthographically irregular words. Premorbid intelligence can be estimated from ART based on the rationale that the reading ability of irregular word correlates strongly with measure of IQ in healthy adults (Nelson and Willison, 1991;Crawford et al, 2001;Yi et al, 2017), and is relatively resistant to cognitive declines in patients with neurological or psychiatric disorders (Sasanuma et al, 1992;McGurn et al, 2004;Matsuoka et al, 2006). It is assumed that better performance on ART implies prior knowledge of a word's pronunciation and therefore a higher premorbid intelligence (Lezak et al, 2004).…”