RTW is a program designed to REDUCE THE NEGATIVE EFFECTS of injury and illness on the employee. RTW is a well designed program to provide a support in navigating medical and disability benefit, planning the return to work as early as possible and giving an opportunity to do light duty assignment to the injured worker.
The main objectives of RTW program are to return the injured employee to work quickly and SAFELY and IDENTIFY & MANAGE their temporary or permanent disability.
So RTW program will involve in the managing the burden of prolonged sickness absenteeism as well as assessing the impairment caused by the injury/illness to the worker.
Here is the Guide For Managing The Return To Work by Canada Human Right Commission.