Cognitive Domain Impairments Related to Walking Difficulty: A Harmonized Cognitive Assessment Protocol Study

TL;DR

This study finds that executive function cognitive impairment is strongly linked to walking difficulty in older adults, and combining it with other impairments increases the risk further.

Contribution

The study introduces a harmonized protocol to assess how specific cognitive domain impairments, alone and in combination, relate to walking difficulty in older adults.

Findings

Executive function impairment had the highest prevalence of walking difficulty (27.2%) compared to other cognitive domains.

Executive function impairment alone significantly increased the odds of walking difficulty, but other single domain impairments did not.

Combining executive function impairment with language fluency or memory impairments further increased the odds of walking difficulty.

Abstract

Community-dwelling older adults with cognitive impairment are at risk of disability. This study aimed to identify if adding specific cognitive domain impairments increase the odds of walking difficulty beyond single domain impairments. We analyzed data from 3,374 community-dwelling older adults (mean[SD] age: 74.1[7.6] yrs, 55.5% female, 80.5% non-Hispanic White) in the Health and Retirement Study Harmonized Cognitive Assessment Protocol, a data-source for cognitive aging research. A validated algorithm was used to classify cognitive domain impairment for executive function (EXF), memory (MEM), language fluency (LFL), visuospatial (VIS), and orientation (ORI). Difficulty walking (≤1 block) was identified using participants’ self-report. We first calculated the prevalence of difficulty walking for each domain impairment. Next, we estimated age, sex, and race/ethnicity-adjusted odds of difficulty walking (aOR[95%CI]) for each domain impairment alone, and then in the presence of another domain impairment. The prevalence of difficulty walking was highest for EXF impairment (27.2%), followed by ORI (25.5%), VIS (19.1%), MEM (14.8%), and LFL (10.4%), relative to 13.6% without any domain impairment. Compared to no impairment, the odds of difficulty walking were greater with EXF impairment (2.23 [95%CI:1.41,3.52]), but no other single domain impairments (P > 0.05). EXF impairment increased the odds of difficulty walking beyond MEM (MEM+EXF:3.65[95%CI:1.36-9.84] and LFL (LFL+EXF: 8.57[95%CI:2.26-32.56]), but no other dual-domain impairments increased the odds above referent EXF, MEM, LFL, VIS, ORI impairments alone. To enhance clinical outcomes, further research must examine the consistency of relationships of EXF impairment, alone and with other domains, across meaningful measures of older adult function.