The Relation between Work Ability Index and Physical Work Capacity based on Fox Equation for VO2 Max in Male Nursing Staff of Isfahan Hospitals, Iran

The correct appraisal of the employee's work ability is important for employers in the economic viewpoint. Improving the personnel's work ability is a way to increase the productivity of human resources in industries and organizations. The purpose of this research was to evaluate the ability of employees by work ability index (WAI) and physical work capacity (PWC) and to find a correlation between the two indices. Determining the PWC index based on WAI values for the purpose of saving costs and time of PWC measurements was another aim of this project. The present analytic, cross-sectional study included 228 randomly selected registered nurses from hospitals in Isfahan, Iran. The WAI and PWC were measured through the WAI questionnaire and Fox equation and by using an ergometer bicycle, respectively. The resulting data was analyzed using SPSS16. Mean values of WAI and PWC among the studied population were 38.25 ± 4.4 and 4.45 ± 0.7, respectively. Pearson's correlation test showed no significant correlations between PWC and WAI in different age groups (r = 0.3; P > 0.05). Multiple linear regression analysis showed that the variables of age and diagnosed diseases were the most effective factors of WAI (β = 0.18; P > 0.05). Pearson's correlation test revealed a significant correlation between the number of diagnosed diseases and PWC index in the age group of 40-49 years. Average WAI in this research, like other studies on similar jobs, was at the acceptable level of > 36. WAI and PWC in different age groups were not significantly correlated (r = 0.3; P > 0.05). Thus, there are essential discrepancies in work ability evaluations made by each index and it is not possible to predict PWC index using WAI values. Given the PWC results and the level of nursing staff's activity (low, medium), the WAI is a suitable instrument to evaluate the professional's abilities. This study revealed that 27.6% of individuals were subject to medium-low work ability risk (WAI < 37) which was 1.8 times more than of the values determined by Finland's Professional Health Institute. Such findings might be caused by shift working and increased working hours.