What do 'background checks' mean in DLA-PIP?

My sister has not been out of the country, except for one week, in the last five years.
The friend who called to start the application was asked the same question you were asked, george42, "has she been out of the country for more than 4 weeks in the last 3 years?" and they answered "no" to that.
The person who called today to chase the non-arrival of the PIP2, was told that PIP2's are now never sent until 'background checks' have been done. Don't know if that is true, but that is what they were told. And they were told that because 'background checks' have not yet been returned, that was was the reason no form had been sent in three weeks.
It does seem strange that basic residency checks can't be carried out in three weeks.

Thank you Gordon and Mrs Hurtyback for your replies.
Maybe this 'background check' line was just an excuse because the PIP2 had not been sent as it should have?
It was a bit anxiety provoking, Gordon, . But my sister has no reason to fear any checks.
In posting my question, I was mainly wondering if this 'checking' meant they would have already contacted the GP for a report? As I would like to have a chat with the GP about some of my sister's current challenges.
Sorry, this is all a bit new to me. I am reading through the excellent B&W guides as fast as I can. Do you know if supporting evidence, like doctors reports, is requested before a PIP2 is filled in? Thanks.

No, medical evidence will not be requested before a PIP2 has been returned. In fact, it is unusual for to be requested at all!

Oh, thank you, Mrs Hurtyback for that info.
And thank you so much Mrs H and Gordon for being moderators for this great forum. I really appreciate you giving your time and expertise to help those of us who know less.
Very Best Wishes

Mrs Hurtyback wrote: No, medical evidence will not be requested before a PIP2 has been returned. In fact, it is unusual for to be requested at all!

Sadly, this is very true. My own GP confirmed this during my last visit when I asked about the issue and tried to get a support letter. My GP sadly shook their head and admitted that the DWP hardly ever contact them and request any records or evidence and furthermore any support letters they write are completely shunned and ignored by the DWP.