Hi Toks
It is normal, due to the length of time waiting for an assessment, claimants may have hospital appointments, what the call does is to make sure the claimant will be available on a certain day at a certain time, if a claimant cannot make it due to hospital /specialist appointment then they can change the date and time without being penalised.
Gary
Nothing on this board constitutes legal advice - always consult a professional about specific problems