With '贈 (posthumously conferred)' added, it's obvious that Osumi was deceased at that time, and it is presumable that the date of his death had been between 701 and 716 since the rank of Jugoinojo was used in and after 701.
「贈」とあるため大隅がこのとき故人であったことがわかり、従五位上は大宝元年（701年）以降に用いられたから、没年は701年から716年の間と推測できる。