Re pips capita telephone interview

Hi my partner had been getting dla for 8 years and moved to pips 3 years ago his claim is up in August this year and he got a renewal form basically asking had anything changed since his last face to face assessment. As he has recently been diagnosed with copd I put it on his form .He was scheduled to go for a face to face last week but was cancelled. On Friday past he got a phone call from capita arranging a telephone interview for next week .Has anyone any information on how this is conducted and what questions he is likely to be asked x