Interpreting executive and lower-order error scores on the timed subtests of the Delis-Kaplan Executive Function System (D-KEFS) battery: Error analysis across the adult lifespan. Issue 10 (25th November 2020)

• Record Type: Journal Article
• Authors: Suchy, Yana; Mullen, Christine M.; Brothers, Stacey; Niermeyer, Madison A.
• Is Part Of: Journal of clinical and experimental neuropsychology. Volume 42:Issue 10(2020)
• Page Start: 982
• Page End: 997
• Publication Date: 2020-11-25
• Subjects: Executive functioning -- processing speed -- accuracy -- errors -- construct validity; Neuropsychology -- Periodicals; Psychophysiology -- Periodicals; Neurosciences -- Periodicals; Psychophysiology -- Periodicals; Societies, Medical -- Periodicals; 616.89
• DOI: 10.1080/13803395.2020.1832203
• Languages: English
• ISSNs: 1380-3395

Abstract

ABSTRACT: Objective: The Delis-Kaplan Executive Function System (D-KEFS) is a battery of tests designed to measure executive functions (EF). Additionally, the D-KEFS contains lower-order tasks, designed to control for speed of visual scanning, sequencing, and verbal and graphomotor output. The construct and criterion validities of D-KEFS scores that are time-based are well established. However, the constructs measured by the D-KEFS error scores are poorly understood, making clinical interpretations of such scores difficult. This study examined the construct validity of D-KEFS errors committed on EF tasks and tasks designed to measure lower-order processes (i.e., non-EF tasks), across the adult lifespan. Method: Participants were 427 adults (18–93 years) who completed the timed subtests of the D-KEFS. Four hundred two participants also completed the Push-Turn-Taptap (PTT; a separate measure of EF) to allow cross-validation. Results: General linear regressions showed that D-KEFS errors committed on the EF tests were associated with EF timed performance (assessed using the D-KEFS time-based scores and the PTT), but only among older adults. Importantly, errors committed on the D-KEFS tasks of lower-order processes were also associated with D-KEFS time-based EF performance, and this relationship held across the adult lifespan. Conclusions: These findings suggest that among older adults EF errors on the D-KEFS can be interpreted as indices of EF, but such interpretations are not automatically warranted for younger adults. Additionally, errors committed on non-EF tasks contained within the D-KEFS battery can be interpreted as reflecting EF weaknesses across the adult lifespan.