Ecological validity of performance-based measures of executive functions: Is face validity necessary for prediction of daily functioning?

Predicting patients' ability to engage in instrumental activities of daily living (IADLs) is an important part of neuropsychological evaluation of older adults. Executive functioning (EF) is the neurocognitive domain most strongly associated with performance of IADLs. However, performance-based tests of EF have long been criticized for having poor ecological validity, largely because of their imperfect association with functional outcomes and their low face validity. However, past research has not examined whether high face validity improves a test's ability to predict IADLs. The present study examined this question. Fifty community-dwelling older adults completed 2 measures of EF that have been previously shown to be related to performance on IADL tasks: the Pillbox Test (a test with high face validity) and the Push-Turn-Taptap task (PTT; a test with low face validity). As an outcome variable, weekly pill counts were conducted across 8 weeks as an index of real-world daily medication management. Hierarchical linear regression analyses and receiver operating characteristic (ROC) curve analyses using medication management as the dependent variable revealed that the PTT outperformed the Pillbox Test both in accounting for variance in medication management and in classifying participants according to their medication management accuracy. The present study does not support the notion that face validity, in and of itself, improves the ability of performance-based EF tests to predict functional outcomes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).