Touch Your Toes! A Brief Measure of Executive Function in Older Adults
With approximately 5.7 million Americans facing the individual, social, and financial burdens of the dementia stage of Alzheimer's disease, brief and valid cognitive assessments are essential for practitioners treating older patients with subjective and objective cognitive concerns.1
In a 2014 AARP survey of individuals 34 to 75 years of age, 93% of the 1,200 respondents thought maintaining or improving cognitive health was very or extremely important.2 Furthermore, a recent report from the Healthy Brain Initiative found 1 in 9 adults 45 years of age and older report increased confusion or memory loss, with one-half of these individuals identifying disruptions in everyday tasks such as cooking, cleaning, and medication adherence.3
While memory functioning is a common concern for individuals as they grow older, the higher-level cognitive processes known as executive function (EF) abilities (eg, attention, inhibitory control, working memory) are some of the cognitive domains most likely to show age-related declines.4-6
Adults with subjective cognitive decline report disruptions in maintaining concentration or switching attentional focus among multiple stimuli (ie, attention) and inhibiting one's attention to irrelevant details (ie, inhibitory control)—two components of EF necessary for many everyday tasks. Cooking, for example, requires keen focus on the necessary steps of a recipe, many of which contain multiple tasks to be done at once that require the inhibition of irrelevant ingredients or distractions.
Current measurement of EF in older adults tends to be computer based in a laboratory setting and thus lacks generalizability to real-world scenarios such as cooking.7 This article describes a brief measure of EF, the Head-Toes-Knees-Shoulders Task (HTKS),8 which is low cost, easy to administer, and involves motoric engagement and social interaction in ways that existing EF measures do not. It's a gamelike behavioral measure administered between participant and examiner originally designed to assess aspects of attention, inhibitory control, and working memory in children.9,10
The HTKS has recently been adapted for use with community-dwelling older adults and has strong potential to be used by practitioners interested in assessing patients' current EF levels; the authors have been published on this subject.11
In the validation study, all participants advanced to the third section and completed the 30 test items.11 The examiner scores the participants' responses based on how well they can follow the directions and do the opposite to a given command. Scores range from 0 to 60, with higher scores indicating higher EF levels.
In addition to the total score, a modification for older adults included measuring how long (in seconds) each participant takes to complete the HTKS. Therefore, a second outcome measure (ie, completion time) is generated using a digital stopwatch (available on most smartphones) beginning at the start of the HTKS task instructions and ending on the final behavioral response to the task. Faster completion times indicate better EF, as shorter completion times show more efficient cognitive processing.
The HTKS is currently available for research to those who submit an online request at http://health.oregonstate.edu/labs/kreadiness/resources. Clinical use will be possible in the future when norms are developed. Online training, which is required for researchers who intend to use the HTKS, can be obtained upon completion of the online request form.
The Validation Study
Participants were predominately female (72%), Caucasian (95%), self-identifying as Not Hispanic or Latino/Latina (96%), married (62%), well-educated (81% had at least a Bachelor's degree), and relatively healthy; self-reported mental and physical health was slightly better and more homogenous than in the general US population. Of the 150 participants in the study, 31 reported subjective memory loss in the past year.
Upon providing informed consent, participants were given a paper-and-pencil questionnaire that collected information on demographics, subjective memory loss (via a single item from the Cognitive Module of the Behavioral Risk Factor Surveillance System),3 and self-reported health (via the 12-item short-form health survey).12 The research protocol continued with HTKS administration and the question, "Would you be interested in playing a game similar to the task you just completed in other studies?" to explore whether participants may be receptive to engaging in gamelike tasks such as the HTKS in future research. This was followed by the National Institutes of Health (NIH) Toolbox for the Assessment of Neurological and Behavioral Function Cognition Battery (NIHTB-CB).13
The validation study showed that the HTKS reliably measured components of EF that have been identified in studies using the "gold standard" measures from the NIH Toolbox.11 In this relatively healthy older adult sample, many participants' total scores were close to perfect (M=57.03, SD=4.42; 83% of the sample obtained scores between 56 to 60).
However, the HTKS completion time showed more variability in scores (M=4 min, 43 s, SD=29.92 s, Range=3 min, 56 s–6 min, 53 s) and could potentially be used in combination with the total score to assess EF.
Regression analyses showed higher DCCS scores (b=-0.75, SE=0.25, p<0.01) and higher Flanker scores (b=-0.67, SE=0.27, p<0.05) significantly related to faster HTKS completion time after adjusting for the influences of age, processing speed, and subjective health ratings and explained 18% of the variance and 16% of the variance in HTKS completion time, respectively. Higher HTKS total score was associated with higher scores on the DCCS (r=0.17, p<0.05) but not the Flanker (r=0.07, p>0.05) or List Sort (r=-0.01, p>0.05).
After adjusting for age, processing speed, and subjective health ratings, higher DCCS scores related to higher HTKS total score (b=0.09, SE=0.04, p<0.05) and explained 9% of the variance in HTKS total score. Associations among HTKS and NIHTB-CB measures were strongest for completion time (not total score) as the measure of HTKS performance. Furthermore, regression models explained more variance in HTKS completion time (16% to 18%) than HTKS total score (9%). The validation study revealed the HTKS was a reliable measure and associated with "gold standard" measures of attentional set shifting and inhibitory control.
Implications for Practitioners
Well-known EF measures typically necessitate computer-based equipment that adds preparation time and resource allocation to purchase the necessary equipment. For example, the NIHTB-CB offers iPad administration of its measures for a yearly subscription cost of $499.99. The HTKS expands the cognitive assessment toolkit by offering an alternative, brief measure to assess EF without the need for computer-based equipment.
The HTKS may also have potential for practitioners interested in incorporating the task into routine check-ups as a practical complement to existing measures in the field. A cognitive task that facilitates face-to-face interaction and motoric engagement may promote a more positive atmosphere and overall experience in a medical setting where some patients may feel particularly nervous. In fact, 93% of the participants in the validation study reported interest in future studies that incorporate gamelike tasks such as the HTKS, suggesting older adults may be receptive to engaging in the HTKS protocol.11
Administering measures that are engaging is an important consideration for adherence in the context of medical evaluation.14 Importantly, HTKS administration may not be valid for individuals who understand the directions of the task but are unable to make the appropriate discernable motion due to physical limitations—for example, stroke survivors.
Future Directions and Conclusion
Although the HTKS is currently available for research use, it has strong potential to be used by practitioners interested in a brief, novel means of assessing EF that's low cost, easy to administer, and engaging for their older patients.
For more detailed information on the psychometric evaluation of the HTKS in community-dwelling older adults, see Cerino and colleagues.11 For access to the online request form and information on the required training to use the HTKS for research purposes only, visit http://health.oregonstate.edu/labs/kreadiness/resources.
— Eric S. Cerino; Karen Hooker, PhD; Robert S. Stawski, PhD; and Megan McClelland, PhD, are part of the School of Social and Behavioral Health Sciences at Oregon State University.
Author Note: Correspondence concerning this paper should be addressed to Eric Cerino, School of Social and Behavioral Health Sciences, College of Public Health and Human Sciences, Oregon State University, 401 Waldo Hall, Corvallis, OR 97331. E-mail: firstname.lastname@example.org
2. Brain health important to 93% of Americans, but few know the 5 ways to help maintain or improve it. AARP website. https://press.aarp.org/2015-01-20-Brain-Health-Important-to-93-of-Americans-But-Few-Know-the-5-Ways-to-Help-Maintain-or-Improve-It. Published January 20, 2015.
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