Branching Condition of the Color-Word Interference Test Enhances Prediction of Meta-Tasking in Community-Dwelling Older Adults

Do executive functions explain older adults' health-related quality of life beyond event-based prospective memory?

Previous work has shown that event-based prospective memory (EBPM) predicted health-related quality of life (HrQoL). In the present study, we aimed to examine whether the relationship between EBPM and HrQoL extended to life satisfaction, and whether it persisted after controlling for other cognitive functions related to EBPM, namely executive functions and retrospective memory. We tested two models using structural equation modeling with latent variables in a sample of older adults. In the first model, we assessed whether EBPM predicted life satisfaction and HrQoL; in the second model, we controlled for retrospective memory and executive functions. The first model indicated that EBPM was related to HrQoL. However, in the second model, this relationship was eliminated by executive functions; life satisfaction was not related to any of the cognitive variables. Findings corroborated the link between HrQoL and EBPM, suggesting that such relationship stems from executive functions rather than retrospective memory.

Ecological validity reconsidered: the Night Out Task versus the D-KEFS

INTRODUCTION

Although executive functioning (EF) correlates with execution of instrumental activities of daily living (IADLs), tests of EF have been criticized for having poor ecological validity. Attempts have been made to develop new tests that approximate naturalistic daily tasks. However, the incremental utility of such tests has not been convincingly demonstrated. The Night Out Task (NOT) is a novel measure designed to increase ecological validity. This study examined whether the NOT correlates with traditional lab- and home-based measures of EF and IADLs, and whether it outperforms traditional measures of EF in predicting IADLs.

METHOD

Participants (50 adults aged 60 to 95) completed (1) the Delis Kaplan Executive Function System (D-KEFS) and IADLs in the laboratory, and (2) ecological momentary assessment of EF and daily IADL tasks at home across three weeks (using the Daily Assessment of Independent Living and Executive Skills protocol; DAILIES).

RESULTS

The NOT correlated with a lab-based measure of EF beyond covariates, and lab-based IADLs beyond covariates and beyond the D-KEFS. However, it was unrelated to at-home variables beyond covariates. In contrast, the D-KEFS was a significant predictor of at-home IADLs, and this association was mediated by at-home EF performance.

CONCLUSION

This study provides a preliminary validation of the NOT as a correlate of office-based performances in a primarily college educated white sample. Despite its high face validity, the NOT does not appear to sufficiently tap EF processes needed for home-based IADLs as measured by the DAILIES, although small sample size limits the interpretability of this negative finding.