A fantastic Endeavour, I have always struggled with the concept of having an incentive to encourage staff to come into the office to perform a job they are paid to do, perhaps I’m just old school!
However in my experience even when trying to give incentives to employees to turn up for work, the same old names come up time and time again.
In the past I have found the best method is to firstly manage the performance of the individuals concerned which I’m sure you already have in place.
Secondly create a performance matrix that runs at team level which includes attendance.
The team owns the targets and generally the team then manages those individuals that may stop them from winning the incentive.
The other thing that you may want to check out is discriminating against an employee whose sickness is linked to a much wider issues with their health generally.
I’m of the believe that you either do it or you don’t i.e. if your off your off and impacted otherwise you may find yourselves writing a very long list of exceptions. This also ensures a consistent approach so when you go to give out the incentive you don't find yourselves with appeals for being unfair.
The other thing that comes to mind as a last resort
“If you can’t change the people, change the people”
It’s a very interesting topic, and one that also opens up discussion around ideal culture, environment and performance management all of which drive some of the behaviors around attendance.