Work Ability Index: Validation of the Greek Version and Descriptive Data in Heavy Industry Employees

Aims: Validation of the Greek version of Work Ability Index (WAI).
Study Design: A cross sectional survey of 943 workers from a shipyard industry.
Place and Duration of Study: University of Patras, Medical School, Public Health Department, HSY occupational health department, Greece in 2006-07.
Methodology: The translation and cultural adaptation of the questionnaire was performed according to the international standards. The following aspects of the questionnaire were evaluated: construct validity, using factorial analysis, and discriminant capacity, by comparing Work Ability Index scores across variables likely to be related with work ability, like absenteeism; criterion validity, by determining the correlation between self-reported health and Work Ability Index score; and reliability, using Kendall’s tau b coefficient to determine the internal consistency of the questionnaire.
Results: A two-dimensional structure model, interpreted as “subjectively estimated work ability” and “ill-health related ability” of the instrument fits better our study population with some of the subscales load on both dimensions. Good discriminating properties of the tool with sickness absence, education level and high criterion validity using dimensions of health status, were evident. High inter-item Kendall’s tau b coefficients were indicative of satisfactory reliability.
Conclusions: The Greek version of the WAI showed satisfactory psychometric properties thus constituting an appropriate option for evaluating work ability in both individual and population-based settings.