Everyday functioning in relation to cognitive functioning and neuroimaging in community-dwelling Hispanic and non-Hispanic older adults

Abstract

The purpose of this study was to examine how a specific informant-based measure of everyday functioning, the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE; Jorm & Korten, 1988) relates to cognition and structural neuroimaging in a large multicultural, multilingual sample of Caucasians and Hispanics. Cognitive variables included selected subtests from the Spanish and English Neuropsychological Assessment Scales (SENAS; Mungas et al., 2000): Verbal Memory, Object Naming, Verbal Attention Span, Verbal Conceptual Thinking, and Pattern Recognition. The association between the IQCODE and selected neuroimaging variables, hippocampal volume and white matter hyperintensity, was evaluated in a subsample of English- and Spanish-speaking Hispanic individuals. The cognitive variables showed strong bivariate relationships with the IQCODE, although only Verbal Memory and Object Naming independently predicted level of functional ability. Verbal Memory was the strongest predictor of functional status, accounting for 23% of the variance in the IQCODE. White matter hyperintensity was also independently related to the IQCODE, accounting for 18% of the variance. Hippocampal volume was related to the IQCODE in a simple bivariate analysis, but was not an independent predictor of reported functional status after controlling for age. The relationships between cognitive variables and functional status, as well as between the imaging variables and the IQCODE, did not differ across language-ethnic groups.

Fig. 1

Distribution of IQCODE-ORD scores by language/ethnicity group. Percent of individuals in each ethnicity/language group scoring within each IQCODE-ORD level are indicated. (IQCODE-ORD level 1—IQCODE average score ≤ 3.0, level 2–3 < IQ-CODE average score ≤ 3.15, level 3—3.15 < IQCODE average score ≤ 3.30, level 4—IQCODE average score > 3.30. NHE = Non-Hispanic, English test administration, HE = Hispanic, English test administration, HS = Hispanic, Spanish test administration).

Fig. 2

Mean performance (with standard errors) for SENAS Object Naming and Verbal Memory Scales by IQCODE-ORD level. (IQCODE-ORD level 1—IQCODE average score ≤ 3.0, level 2–3 < IQCODE average score ≤ 3.15, level 3 = 3.15 < IQCODE average score ≤ 3.30, level 4—IQCODE average score > 3.30).

Fig. 3

Mean performance (with standard errors) for White Matter Hyperintensity Rating by IQCODE-ORD level. (IQCODE-ORD level 1—IQCODE average score ≤ 3.0, level 2–3 < IQCODE average score ≤ 3.15, level 3—3.15 < IQCODE average score ≤ 3.30, level 4—IQCODE average score > 3.30).

Fig. 4

Mean performance (with standard errors) for Hippocampal Volume (normalized to total intracranial volume) by IQCODE-ORD level. The relationship of HC with IQCODE-ORD was not statistically significant when age was added to the model. (IQCODE-ORD level 1—IQCODE average score ≤ 3.0, level 2–3 < IQCODE average score ≤ 3.15, level 3—3.15 < IQCODE average score ≤ 3.30, level 4—IQCODE average score > 3.30).