Performance-Based instrument to assess functional capacity in dementia: The Texas Functional Living Scale.

Objective: The Texas Functional Living Scale (TFLS) is a new performance-based measure of functional abilities with an emphasis on instrumental activities of daily living skills that is brief and weighted toward cognitive tasks. The purpose of this study was to examine its psychometric properties and clinical utility in patients with Alzheimer disease (AD) and normal elderly individuals.

Background: Measures of daily functional capacities used in patients with dementia often rely upon informant-based behavioral ratings or lengthy assessments of instrumental activities of daily living. Few existing quantitative tools emphasize performance-based cognitively-oriented tasks designed for patients with AD, although there is a need for such measures.

Method: Twenty-two AD patients and 21 healthy controls were administered the TFLS and a measure of global cognitive status (Mini-Mental State Examination). Additionally, informant-based ratings of daily living skills (Blessed Dementia Rating Scale) and emotional and behavioral status (Consortium to Establish a Registry for Alzheimer's Disease Behavior Rating Scale for Dementia) were obtained from caregivers of the AD patients. All subjects were re-evaluated approximately 1 month later using the same instruments.

Results: The TFLS showed a strong correlation with the Mini-Mental State Examination (r = 0.92). At 1 month, test-retest reliability was high, and TFLS subscale scores were highly correlated (r > 0.90 for most) with the total score. The TFLS was moderately correlated with informant ratings of functional skills as assessed with the Blessed Dementia Rating Scale but was unrelated to emotional and behavioral symptoms as assessed with the Consortium to Establish a Registry for Alzheimer's Disease Behavior Rating Scale for Dementia.

Conclusions: The TFLS showed evidence of good reliability, internal consistency, and convergent and discriminant validity with several popular measures of global cognitive status and behavioral functioning. It is a brief and easily administered performance-based measure of daily functional capabilities that is sensitive to level of cognitive impairment and seems applicable in patients with varying degrees of dementia.