Do normative data specific to Greek Australian older adults improve validity of neuropsychological assessment results?

OBJECTIVE: This study aimed to compare Greek Australian and English language normative data with regard to impairment rates yielded within a healthy Greek Australian older adult sample. We also examined whether optimal cut scores could be identified and capable of sensitively and specifically distinguishing between healthy Greek Australians from those with a diagnosis of Alzheimer's disease (AD). METHOD: Ninety healthy Greek Australian older adults and 20 demographically matched individuals with a diagnosis of AD completed a range of neuropsychological measures, including the Wechsler Adult Intelligence Scale-Fourth Edition, Greek Adaptation (WAIS-IV GR), verbal and visual memory, language and naming, and executive functions. Impairment rates derived from the use of either Greek Australian or English language normative data were calculated and compared, using a 1.5 standard deviation criterion to denote impairment. Receiver operating characteristics curve analysis was used to investigate the sensitivity and specificity of alternate cut scores. RESULTS: Impairment rates derived from the Greek Australian normative data showed that rates of impairment generally fell within the expected 7% range. In contrast, impairment rates for all tests derived using English language normative data were significantly higher and ranged from 11%-66%. Comparisons between healthy and AD participants with moderate dementia showed significant differences across all measures. Area under the curve results ranged from .721 to .999 across all measures, with most tests displaying excellent sensitivity and specificity. CONCLUSIONS: English language normative data were found to be inappropriate for use with Greek Australian elders, potentially leading to erroneous diagnostic outcomes. The use of minority group specific normative data and associated cut points appear to partially ameliorate this issue. Clinical implications are discussed alongside future research directions.

Validity of Visuoconstructional Assessment Methods within Healthy Elderly Greek Australians: Quantitative and Error Analysis.

AIMS: Visuospatial skills are frequently assessed with drawing tests. Research has suggested that the use of drawing tasks in low educated groups may lack the ability to discriminate healthy individuals from clinical populations. The aims of this study were to investigate the validity of visuoconstructional tests in a sample of older Greek Australian immigrants and compare their performances to a matched sample of patients with Alzheimer's disease (ad). METHOD: We assessed visuoconstructional performances in a sample of 90 healthy older Greek Australians, with a primary school level of education, and compared performances to a demographically matched sample of 20 Greek Australians with a diagnosis of ad on four visuoconstructional drawing tests: Greek cross, four-pointed star, intersecting pentagons, and the Necker Cube. RESULTS: While healthy participants tended to outperform the ad group on most copy tasks, high fail rates within the healthy sample were observed for the intersecting pentagons and Necker cube (78% and 73% fail rates, respectively) when using established clinical cut-off scores. High rates of curved angle, omission, distorted relation between elements, spatial disorganization and three-dimensional design errors were found across the four-pointed star, intersecting pentagons, and the Necker cube in both healthy participants and those with ad. Exploratory receiver operating characteristic curve analysis revealed that, with perhaps the exception of the Greek cross, meaningful sensitivity and specificity could not be reached for the four-pointed star, intersecting pentagons, and Necker cube. CONCLUSION: Cognitively healthy immigrants with low education appear to be at a disadvantage when completing visuoconstructional drawing tests, as their performance may be misinterpreted as indicating cognitive impairment. Future research is needed to identify alternative approaches to assess visuoconstructional ability in culturally and linguistically diverse older cohorts with limited education.