Validity and reliability of the Work Ability Index in primary care workers in Argentina

This study evaluates the validity and reliability of the Work Ability Index (WAI) in Argentina. An instrument was applied to 100 workers, all agents of Primary Health Care in the county of General Pueyrredon. In the construct validity, the dimensional structure was studied by means of exploratory factor analysis, based on a polychoric matrix and parallel analysis to obtain the number of factors. In the correlation validation, the Spearman correlation was estimated between the WAI and the dimensions of the 36-Item Short Form Health Survey (SF-36). The reliability assessment was measured by Cronbach's alpha estimate. The result of the internal consistency of the scale was 0.80, indicating acceptable reliability. The WAI score yielded the following results: 12% moderate, 50% good and 38% optimal. In the validation process, a three-dimensional structure was identified which accounts for 66% of the total variance of the data through the main components. The theoretical assumptions of the construct validity confirmed the direct and significant correlation between WAI scores and the dimensions of health status assessment, with the highest value in the physical functioning dimension (0.478) and the lowest in the bodily pain dimension (-0.218). It was concluded that the WAI, translated and adapted into Spanish, showed adequate psychometric properties and can therefore be used in association studies between aspects of work and their impact on health.