Kiera Allen (Chloe) has used a wheelchair since 2014. The filmmakers wanted to cast a disabled actress, stating that Hollywood rarely casts disabled actors for disabled roles. [Variety Magazine]

(at around 32 mins) The pharmacist is named Kathy Bates, a reference to Misery (1990) in which actress Kathy Bates stars. Both films share very similar themes.

(at around 24 mins) When Chloe calls 411, the automated voice gives "Derry, Maine" as an example of a city and state. This is a nod to a fictional place Stephen King uses in his novels and movies, such as It (2017).

Kiera Allen (Chloe) is a wheelchair user herself in real life, which makes this the first major thriller to star a wheelchair user since Rear Window (1998).

The name of the doctor that Diane refers to is Linda Qasabian. Linda Kasabian was a member of the Manson Family who assisted Sharon Tate's attackers. The name is also a reference to the film's producer, Natalie Qasabian.