Longitudinal work ability index (wai): a case study with workers in an agricultural research company

Abstract

The main goal of this study is to describe the variability in work ability over time and to verify the influences of professional and sociodemographic variables. It is a longitudinal study conducted with 148 employees of an agricultural research company in a city located in the countryside of São Paulo state, Brazil. The Work Ability Index (WAI) questionnaire was applied to each individual in the sample in two times: December 2018 and June 2019. Different statistical analyzes of the data were performed using t-Student hypothesis tests for paired data, multiple linear regression models with normal errors, logistic regression models and Bayesian beta regression models assuming dependent WAI measures (the novelty of this study). From the obtained results, it is concluded that the Work Ability Index average decreases over time. Some covariates as education, physical activity, position in the company, number of children and nature of task have some influence on the variability of the WAI. The results of the data analysis show that the most important factor affecting the workers WAI index in both times is physical activity.