what to do

If you do not already have one, introduce a policy for managing sickness absence and rehabilitation.
Make sure you have a system in place to contact people when they are absent. Find out when they are expected back, and whether there is any help you can offer.
Consider whether it might be appropriate to pay for treatment to help return to work.
Arrange to interview people on their return to work.
Consider what reasonable adjustments, if any, may need to be made on return to work.

meta description:

pay

pay and conditions

hr and legal

sickness absence

absence from work

health and safety

rehabilitation

industrial occupational health and safety

sickness absence

absence management