PLACE meat, onions and mushrooms in slow cooker.
ADD broth; stir. Cover with lid. Cook on LOW 6 to 8 hours (or on HIGH 3 to 4 hours). Meanwhile, cooking pasta as directed on package, omitting salt, about 20 min. before ready to serve meat mixture.
DRAIN pasta. Mix cream cheese spread and flour. Add to meat mixture; stir until cream cheese is completely melted and mixture is well blended. Place pasta in large bowl. Add meat mixture; toss to coat.