The Pittsburgh Fatigability scale for older adults: development and validation.

Area of Science:

• Gerontology
• Clinical Assessment
• Rehabilitation Science

Background:

• Fatigability is a key factor impacting older adults' mobility and function.
• Existing measures may not fully capture perceived fatigability.
• A validated tool is needed to assess perceived fatigability in older populations.

Purpose of the Study:

• To develop the Pittsburgh Fatigability Scale (PFS).
• To establish the reliability and validity of the PFS against performance measures in older adults.

Main Methods:

• A 26-item scale was developed and reduced to a 10-item PFS using principal components analysis.
• Reliability was assessed via internal consistency (Cronbach's alpha) and test-retest (intraclass correlation).
• Validity was evaluated by comparing PFS scores with performance fatigability, gait speed, physical function, and fitness measures.

Main Results:

• The 10-item PFS demonstrated strong internal consistency (α=0.88) and excellent test-retest reliability (ICC=0.86).
• PFS scores were significantly higher in individuals with greater performance fatigability, slower gait speed, poorer physical function, and lower fitness (P < .001).
• Differences in PFS scores between high and low performance fatigability groups ranged from 3.2 to 5.1 points.

Conclusions:

• The 10-item PFS is a valid and reliable measure of perceived fatigability in older adults.
• The PFS can complement performance-based measures to identify older adults at risk of mobility limitations.
• This scale is suitable for use in clinical and research settings.