Correlation Between Executive Function and Instrumental Activities of Daily Living in Older Adults With Mild to Moderate Dementia

PURPOSE: This study sought to answer the following research question: Is there a correlation between instrumental activity of daily living (IADL) performance and executive functioning in older adults with mild to moderate dementia?

BACKGROUND: In previous studies, IADL variables and neuropsychological deficits have been closely related, but other determinants of IADLs have also recently been identified. For example, neuroanatomical changes may act as a common pathway of deficits in both neuropsychological test performance and IADL performance, explaining their interrelationship. This study’s purpose was to assess whether neuroanatomical and neuropsychological correlates are independently related to IADLs and how these factors can affect executive functioning. By applying the aging process theory, the researchers were able to infer a decline in cognitive ability in older adults. Analysis of the results proved that there is a positive correlation between executive function and IADLs.

DESIGN: There are two variables identified in this investigation, executive function and instrumental activities of daily living. To relate executive function with the performance of IADLs, the researchers used the correlational research method. A correlational study is a quantitative method of research in which two or more quantitative variables from the same group of participants are studied. Nominal data such as sex were used to make possible correlations, but the numerical data provided by the measures selected were used to answer the core research question.

PARTICIPANTS: The test group included older adults diagnosed with mild to moderate dementia living in assisted care facilities in Tallahassee, Florida, and its surrounding areas. Eligible participants met all inclusion criteria: They all were age 65 or older; able to read, write, and verbally communicate in English at a level that was sufficient for the measures used; diagnosed with mild to moderate dementia; and physically and mentally able to participate in the study. Exclusion criteria included younger than age 65, non-English-speaking, no history of dementia, and lack of physical and mental capacity to participate. Once inclusion criteria were met, the individual was given a prescreening questionnaire. Individuals whose answers were satisfactory were administered the assessments.

METHOD: Data were collected through the use of two measures, the Lawton IADL Scale and the Saint Louis University Mental Status (SLUMS) Exam. The Lawton IADL Scale was used to assess independent living skills. The instrument is most useful for identifying how a person is functioning at the present time and improvement or deterioration of IADL performance over time. The SLUMS Exam is a clinician-administered examination used to identify persons who have dementia or mild neurocognitive impairment. It assesses attention and working memory, cognition, and executive function. Raw data were analyzed using one-way analysis of variance, univariant analysis of variance, and nonparametric correlation analysis.

RESULTS: According to the data collected, there is a positive correlation between executive functioning and IADLs. Individuals who completed higher levels of education scored higher on the Lawton IADL Scale and showed higher levels of mental functioning on the SLUMS Exam. Female participants outscored male participants in both variables, executive functioning and IADL performance, while African-Americans scored higher in executive functioning than their White counterparts. White participants scored higher in IADL performance than African-American participants.

DISCUSSION: The findings of this study show a positive relationship between cognitive decline and decreased IADL performance. Individuals who had completed higher-level education, such as a bachelor’s or master’s degree, had a better chance of retaining cognitive functioning. These individuals were able to remain independent longer than their less formally educated counterparts.

IMPACT STATEMENT: Occupational therapists use their knowledge of the aging process to implement interventions that allow older adults to continue to participate in ADLs and IADLs. Clients’ unique perspectives on what is considered independence are maintained throughout the occupational therapy process. This study contributes to existing research concerning daily functioning while aging. For aging in place to occur, signs of cognitive decline must be identified so that preventive measures can be taken.