Reliability and validity of the work assessment scale for persons with multiple sclerosis

Area of Science:

• Rehabilitation research
• Psychometrics
• Neuroscience

Background:

• Multiple sclerosis (MS) significantly impacts an individual's ability to engage in work-related activities.
• Assessing the multifaceted nature of work in MS requires validated instruments.
• The Work Assessment Scale (WAS) was developed to evaluate factors impeding or enhancing work in MS patients.

Purpose of the Study:

• To establish the reliability and validity of the Work Assessment Scale (WAS) in a sample of individuals with multiple sclerosis.
• To analyze the factor structure of the Work-Impeding (WAS-I) and Work-Enhancing (WAS-E) components of the WAS.
• To determine the concurrent validity of the WAS with established measures.

Main Methods:

• The study involved 551 participants diagnosed with multiple sclerosis.
• Varimax rotated factor analysis was employed to examine the factor structures of WAS-I and WAS-E.
• Reliability was assessed using Theta coefficients and test-retest correlations.
• Concurrent validity was evaluated against Activities of Daily Living (ADL) and Symptom subscales.

Main Results:

• Factor analysis yielded a seven-factor solution for WAS-I (33 items) and a five-factor solution for WAS-E (19 items).
• Reliability coefficients (Theta) for WAS-I factors ranged from .73 to .90, and test-retest correlations ranged from .76 to .91.
• Reliability coefficients (Theta) for WAS-E factors ranged from .66 to .81, and test-retest correlations ranged from .68 to .82.
• Significant concurrent validity was found between the WAS and both ADL and Symptom subscales.

Conclusions:

• The Work Assessment Scale (WAS) demonstrates strong psychometric properties, including reliability and validity, for use in individuals with multiple sclerosis.
• The WAS effectively measures both work-impeding and work-enhancing factors relevant to employment, homemaking, and personal care.
• Findings support the use of the WAS as a valuable tool in clinical and research settings for individuals with MS to understand and address work-related challenges.