The following is my opinion, formed from years of running different safety programs.
1-Any program is only going to appeal to a % of your employees, some appeal to a greater percentage than others. But to truly reach most or all of your employees, you will need different programs (not necesarily all incentive programs though).
2-Programs get stale over time, the best programs change behavior and create a self-sustaining culture that persists even if the program is discontinued.
3-Programs have greater success if they focus on addressing the causes of accidents rather than simply reducing accidents.
The most succesful program I ever ran worked as follows:
Employees were placed into teams of 20-25 individuals that worked in close proximity to each other. The teams elected a team captain and choose their team name (this helped to create ownership). The competition was points based, the team with the greatest number of points at the end of the month won (each employee on the team was awarded a $25 gift card). There were also awards for the two individual employees who accumualted the most points even if they were not a winning team (again to number 1 above, this offers recognition of the individual as well as the group. Ealier programs showed that some employees resented being on a lackluster team and this allowed them to strive for recognition even if the team as a whole did not). Points were reduced for accidents and injuries but they were minor deductions (5-10 points), unreported accidents and injuries would cost the team 100 points. But the only way to earn points for your team was by completing pre-printed cards. The cards allowed you to list that you had:
A-Mentored a co-worker on safety. This could have been anything from coaching a coworker observed lifting incorreclty on proper lifting, to reminding a coworker of the rules for PPE. The employees were required to list the who/what and when of their coaching.(worth 5 points)
B-Addressing workplace safety. This could be anything from noting a burned-out light or blocked fire extingisher to picking up paper debris or other tripping/slipping hazards. (worth 5 points)
C-Making a suggestion to improve workplace safety. This is the big one and worth 50 points. We had restrictions on suggestions as they had to be valid-no frivilous suggestions, and nothing that had been previously posed. A suggestion that is incorporated into the workplace has the potential to make profound differences to the organization, so we really wanted to emphasize these actions.
The focus of the program was employees taking ownership of the facility, watching each other and dealing with all the issues that lead to injury. Very little focus was placed on reducing incidents.
As a reasult, we had teams pulling in thousands of points per month, our facilities never looked better and our accident/injury/unreported damage rates plummeted.
There is quite a bit more to the program, but this is a basic overview.