The Wallace Foundation released a study that highlighted a few key attributes that make for a sustainable after school program for middle schoolers.
The basic findings:
1. Provide youth with as much leadership opportunities as possible.
2. Staff must have a pulse on what goes on in the students lives outside of program
3. Program is community-based
4. Staff discuss the program at least 2 times per month (I say the more the better)
5. 100 or more youth enrolled per year
Find the entire report here.
The Wallace Foundation has a wealth of research on after school programming.