Yes, you should be in touch with them to make sure you are covering all their work and appointments and to get an update as to how they are feeling and when they think they may be able to return to work. How often you call them depends on what’s wrong with them and how long they are signed off for. For example, if they have been signed off for a month you could call at the 2 week point and again a day or so before the fit note expires for an update.