An item response theory analysis of the Executive Interview and development of the EXIT8: A Project FRONTIER Study.

INTRODUCTION: The Executive Interview (EXIT25) is an effective measure of executive dysfunction, but may be inefficient due to the time it takes to complete 25 interview-based items. The current study aimed to examine psychometric properties of the EXIT25, with a specific focus on determining whether a briefer version of the measure could comprehensively assess executive dysfunction. METHOD: The current study applied a graded response model (a type of item response theory model for polytomous categorical data) to identify items that were most closely related to the underlying construct of executive functioning and best discriminated between varying levels of executive functioning. Participants were 660 adults ages 40 to 96 years living in West Texas, who were recruited through an ongoing epidemiological study of rural health and aging, called Project FRONTIER. The EXIT25 was the primary measure examined. Participants also completed the Trail Making Test and Controlled Oral Word Association Test, among other measures, to examine the convergent validity of a brief form of the EXIT25. RESULTS: Eight items were identified that provided the majority of the information about the underlying construct of executive functioning; total scores on these items were associated with total scores on other measures of executive functioning and were able to differentiate between cognitively healthy, mildly cognitively impaired, and demented participants. In addition, cutoff scores were recommended based on sensitivity and specificity of scores. CONCLUSION: A brief, eight-item version of the EXIT25 may be an effective and efficient screening for executive dysfunction among older adults.

A brief Spanish-English equivalent version of the Boston Naming Test: a Project FRONTIER study.

The Boston Naming Test is a neuropsychological measure of confrontation naming, short forms of which can be advantageous with various populations. The purpose of this study was to establish a Spanish-English equivalent version of the BNT using item response theory. Data were analyzed from 380 Project FRONTIER participants; 27 items differed between groups and were removed from the measure. Additionally, 18 items did not differ between groups but were poor items. The current 15-item Spanish-English equivalent version of the BNT offers significant advantages. Future work is required to validate the diagnostic utility of the instrument in various settings and populations.

Normative performance on the Brief Smell Identification Test (BSIT) in a multi-ethnic bilingual cohort: a Project FRONTIER study.

The Brief Smell Identification Test (BSIT) is a commonly used measure of olfactory functioning in elderly populations. Few studies have provided normative data for this measure, and minimal data are available regarding the impact of sociodemographic factors on test scores. This study presents normative data for the BSIT in a sample of English- and Spanish-speaking Hispanic and non-Hispanic Whites. A Rasch analysis was also conducted to identify the items that best discriminated between varying levels of olfactory functioning, as measured by the BSIT. The total sample included 302 older adults seen as part of an ongoing study of rural cognitive aging, Project FRONTIER. Hierarchical regression analyses revealed that BSIT scores require adjustment by age and gender, but years of education, ethnicity, and language did not significantly influence BSIT performance. Four items best discriminated between varying levels of smell identification, accounting for 59.44% of total information provided by the measure. However, items did not represent a continuum of difficulty on the BSIT. The results of this study indicate that the BSIT appears to be well-suited for assessing odor identification deficits in older adults of diverse backgrounds, but that fine-tuning of this instrument may be recommended in light of its items' difficulty and discrimination parameters. Clinical and empirical implications are discussed.