Work Ability Index: Psychometric Testing in Aeronautical Industry Workers

Area of Science:

• Occupational Health
• Psychometrics
• Health Surveillance

Background:

• The Work Ability Index (WAI) is an international instrument for measuring work ability.
• Adaptations of the WAI are necessary for diverse national contexts.
• This study focuses on the psychometric evaluation of the Spanish WAI version.

Purpose of the Study:

• To evaluate the psychometric properties of the Spanish version of the Work Ability Index (WAI).
• To establish the reliability and validity of the WAI for use in Spain.

Main Methods:

• A methodological design was employed with a sample of 233 workers in the Spanish aeronautical industry.
• Reliability was assessed using internal consistency (Cronbach's alpha, item-total correlation).
• Validity was tested through confirmatory factor analysis, known groups, and convergent validity.

Main Results:

• The Spanish WAI showed adequate internal consistency.
• Confirmatory factor analysis supported a two-factor solution: "Subjectively estimated work ability and resources" and "Ill-health-related".
• Higher WAI scores were observed in workers under 45; convergent validity was supported by a strong correlation with self-assessed health status.

Conclusions:

• The Spanish WAI version is reliable and valid, suitable for occupational health professionals.
• The identified two-factor structure aligns with international findings.
• Further research is recommended to address discrepancies in subscale functioning across studies.