What is the scoring system for the Functional Assessment Staging (FAST) evaluation for Alzheimer's disease?

Functional Assessment Staging (FAST) Scoring System for Alzheimer's Disease

The Functional Assessment Staging (FAST) scale is a validated clinical assessment tool that evaluates functional deterioration throughout the entire course of Alzheimer's disease, with scores ranging from normal aging to severe dementia stages. 1

FAST Scale Scoring System

The FAST scale divides the progression of Alzheimer's disease into 7 major stages with several substages, focusing on functional abilities:

• Stage 1: Normal adult - No functional decline 1
• Stage 2: Normal older adult - Subjective complaints of forgetting location of objects; subjective work difficulties 1
• Stage 3: Early Alzheimer's disease - Decreased job functioning evident to co-workers; difficulty traveling to new locations 1
• Stage 4: Mild Alzheimer's disease - Decreased ability to perform complex tasks (e.g., managing finances, preparing meals) 1
• Stage 5: Moderate Alzheimer's disease - Requires assistance in choosing proper clothing 1
• Stage 6: Moderately severe Alzheimer's disease - With substages:
  • 6a: Difficulty putting clothing on properly 1
  • 6b: Unable to bathe properly; may develop fear of bathing 1
  • 6c: Inability to handle mechanics of toileting 1
  • 6d: Urinary incontinence 1
  • 6e: Fecal incontinence 1
• Stage 7: Severe Alzheimer's disease - With substages:
  • 7a: Speech limited to about 6 words or fewer 1
  • 7b: Speech limited to a single word 1
  • 7c: Loss of ambulatory ability 1
  • 7d: Unable to sit up independently 1
  • 7e: Unable to smile 1
  • 7f: Unable to hold head up 1

Clinical Application and Interpretation

• FAST is administered by interviewing the care partner or the patient (if at a mild stage) to determine the level of impairment 2
• Each stage is rated on a 4-point scale (0,1,2,3) with the description that best fits the person's performance indicating the level of impairment 2
• The total score range is 0-60, with higher scores indicating greater dependence 2

Validation and Clinical Significance

• FAST has been validated in both primary and specialty care settings and can be administered by clinical or non-clinical staff 2
• Studies show significant correlations between FAST and other cognitive assessment tools including MMSE (r= -0.71, p<0.001), CDR, and ADL scales 3
• FAST is particularly valuable for tracking the longitudinal course of AD, even in its most severe stages when other cognitive tests reach floor effects 1

Advantages of the FAST Scale

• Spans and describes the entire course from normal aging through progressive AD until the final substages 4
• Enhances ability to track the longitudinal progression of Alzheimer's disease 4
• Provides valuable diagnostic, differential diagnostic, and prognostic information 4
• Based on the Global Deterioration Scale (GDS) for typical AD dementia, but with more detailed functional assessment 2

Important Clinical Considerations

• In typical AD, symptoms progress in sequence through the stages, but atypical dementias may not follow this sequence 2
• FAST has been shown to elucidate a characteristic pattern of progressive, ordinal functional decline in AD across different populations 3
• The scale is particularly useful for evaluating severe stages of dementia when cognitive tests are no longer sensitive 1
• FAST can help determine eligibility for palliative or hospice care in patients with severe dementia 2

FAST provides clinicians with a structured approach to assess and monitor functional decline in Alzheimer's disease patients, offering valuable insights for care planning and disease management throughout the entire disease course.