*3.3. Work Ability Index of Workers with Disabilities*

Both the RTW and non-RTW groups included individuals with a diverse age range from around 26 to 55 years old, as shown in Table 1. Based on the line graph, it was determined that the average work ability index for disabled workers was 39.29. (SD 4.39). Figure 2 provides a detailed illustration of the work ability index based on the age and work period, and the work ability index after research [16] revealed that there was also a correlation between age and the index.

**Figure 2.** Distribution score of the work ability index based on the age and working period.

According to the description in Figure 2, the distribution score of the work ability index sets the majority of the data in the "good" category for a group of workers participating in the RTW program, which was between 37 and 44 [17]. Conversely, those who were disabled but did not participate in the RTW program showed a lower score of WAI. The use of WAI analysis among employees with disabilities in this research, which were practically in the same context as the study [17,18] of the work ability index in the population of people receiving state insurance, was accomplished.

The results in Figure 3 indicate that the work ability index (WAI) of disabled workers who participated in the return to work (RTW) program appeared to be higher compared to those who did not participate in the RTW program. Specifically, the average WAI score of disabled workers in the non-RTW group was 37%, which is considered poor, while the RTW group had a higher proportion of disabled workers with an excellent WAI score of 28 (12.20%). Furthermore, there were no disabled workers in the poor category after participating in the RTW program, implying that the RTW program is associated with an increased work ability index score of disabled workers, however, it is important to recognize the implication of this research for further study to investigate the causality that the RTW program is effective in enhancing the work ability index of disabled workers.

**Figure 3.** Work ability index dynamic value based on the category.
