Psychometric Properties of the Spanish Version of the Work Ability Index in Working Individuals


It is increasingly important to have validated instruments to assess the ability to work. Thus, the aim of this study was to evaluate the psychometric properties of the Spanish version of the Work Ability Index (WAI) in working individuals. A cross-sectional study was conducted on 360 workers (men and women) in a high-complexity public hospital and in a public university. The participants were between 40 and 75 years, with a contract of at least 11 h weekly. The ability to work was assessed using the WAI and the perception of health through the Short Form 36 Health Survey version 2 (SF-36 v2). The concurrent validity was analyzed, correlating the WAI with the SF-36 v2. An exploratory factor analysis was performed to test construct validity. In addition, the internal consistency of the WAI was analyzed using the standardized Cronbach’s alpha coefficient. The WAI showed a positive and statistically significant correlation (p < 0.001) with the SF-36 v2. The exploratory factor analysis showed three factors interpreted as, “Mental Resources”, “Diseases and Health-Related Restrictions”, and “Self-perception of Work Ability”. The reliability of the factors was acceptable, except for the second factor, which was poor. The WAI demonstrated acceptable psychometric properties, such as internal consistency, concurrent and construct validity, constituting a reliable instrument to measure work ability for the population of active working individuals in the service sector.

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Dr. Leticia Miller and Norma Peralta of the Republic of Argentina for having facilitated the Work Ability Index in its Spanish version. The Risk Prevention units of the Hospital Dr. Hernán Henríquez Aravena (Eng. Nataly Martínez and her work group) and the Universidad de La Frontera (Eng. Katipza Yaksic and her work group). The Dirección de Investigación of Universidad de La Frontera (DIUFRO) project number SSS17-0001. Students in the Physiotherapy program at the Universidad de La Frontera for their help in data collection: Bastián Sáez, Mauricio Salazar, Sofía Tapia and María José Uribe. Camila Salazar and Andrés Concha for their review of the manuscript. Thanks to Dr. Helen M. Lowry for proofreading the article.


This study was financed by the Chilean Institute for Safety in the Workplace (IST) (ID#9, “Capacidad de trabajo y pruebas funcionales en adultos mayores chilenos laboralmente activos”, 2017–2020).

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Correspondence to Gabriel Nasri Marzuca-Nassr.

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Conflict of interest

Claudio Bascour-Sandoval, Francisco Soto-Rodríguez, Claudio Muñoz-Poblete and Gabriel Nasri Marzuca-Nassr declare that they have no conflict of interest.

Ethics Approval

The study was conducted under the guidelines of the Declaration of Helsinki [38]. Thus, it had the approval of the Ethics Committee of the Universidad de La Frontera (ACTA N°013_18) and the South Araucanía Health Service (0000004 19.01.2018).

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Bascour-Sandoval, C., Soto-Rodríguez, F., Muñoz-Poblete, C. et al. Psychometric Properties of the Spanish Version of the Work Ability Index in Working Individuals. J Occup Rehabil 30, 288–297 (2020).

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  • Workers
  • Psychometric properties
  • Work Ability Index
  • Reliability
  • Validity