This movie is NOT a sequel to the 1990 movie. It is a remake, a re-imagining, or a version of the previous movie and has no other connection to it at all. Although Kiefer Sutherland appears in both versions, he plays two different characters.
Ellen Page also voiced and motion captured the lead character Jodie Holmes from the 2013 video game Beyond: Two Souls (2013). The game explores the "infraworld" which is analogous to the world after death where the souls reside. Ellen Page's character in the game also experiences supernatural activities and communicates with entities from the "other side."