Research Article: How do impairments in cognitive functions affect activities of daily living functions in older adults?

Date Published: June 7, 2019

Publisher: Public Library of Science

Author(s): Meng-Ta Lee, Yuh Jang, Wan-Ying Chang, Marco Innamorati.

http://doi.org/10.1371/journal.pone.0218112

Abstract

The assessment of daily living activities could provide information about daily functions and participation restrictions to develop intervention strategies. The purposes of this study were to assess the scores of the Barthel Index (BI) and Lawton Instrumental Activities of Daily Living (IADL) scale in older adults with cognitive impairment and to explore the different effects that levels of cognitive functions have on changes in IADL functions. We recruited 31 participants with dementia, 36 with mild cognitive impairment (MCI), and 35 normal controls (NCs) from the neurology outpatient department of a regional hospital. The results of the demographic and clinical characteristics through the Lawton IADL scale, BI, Quick Mild Cognitive Impairment (Qmci) screen, Montreal Cognitive Assessment (MoCA), and Mini-Mental State Examination (MMSE), were collected on the same day and compared with the Kruskal–Wallis test, Wilcoxon rank-sum test, Fisher’s exact test, and a multiple linear regression analysis, as appropriate. In the BI, bathing was the most discriminating activity to differentiate patients with MCI and dementia; in the Lawton IADL scale, medication responsibility and shopping were the most discriminating activities to differentiate NCs and patients with MCI, and patients with MCI and dementia, respectively. In addition, the predictors of changes in Lawton IADL scale scores were the problem-solving score of the Clinical Dementia Rating scale, a Qmci score of > 20.4 and an age of ≤ 81.2 years, a MoCA score of < 9.4 and an age of > 81.2 years, and the MMSE score and an age of > 81.2 years. This study adds to the evidence that the description of basic and instrumental daily activities is integrated in older adults with cognitive impairment. Notably, the Qmci is the most significant predictor of changes in IADL function for “young” older adults, as are the MoCA and MMSE for “old” older adults.

Partial Text

The number of people older than 65 years has been increasing worldwide [1]. The global prevalence of dementia is 1.2%–7.2% [2], and the population of older adults with dementia is expected to increase concurrently with global aging. The reported proportion of individuals with mild cognitive impairment (MCI)—at 5.0%–36.7% [3]—is higher than that of people with dementia; however, most cases of MCI and dementia in older adults remain underdiagnosed and unidentified.

This study demonstrated that the cut-off value of 81.2 years for age might be considered a threshold for the deterioration of daily living function in older adults in clinical practice. Moreover, cognitive instruments such as the CDR scale, Qmci, MoCA, and MMSE play complementary roles in predicting the changes in IADL functions for older adults. Remarkably, the Qmci is the most statistically significant factor in predicting the changes in IADL function for young older adults, as are the MoCA and MMSE for old older adults. In addition, we recruited participants not only with MCI but also with dementia to integrate the description of IADL and BADL functions in older adults with a spectrum of cognitive impairment. In the Lawton IADL scale, medication responsibility, shopping, and finance-handling are the optimal indicators for discriminating between the NCs and the participants with MCI, the participants with MCI and dementia, and the participants with mild and moderate dementia; however, in the BI, bathing and grooming are the optimal indicators for discriminating between the participants with MCI and dementia and the participants with moderate and severe dementia.

 

Source:

http://doi.org/10.1371/journal.pone.0218112