Chronological schematic of experimental design.Note: 1. Duration of index hospitalization is ≤10 days. Time from hospital discharge, ER, or physician’s office visit (due to the recent exacerbation) to Randomization (Visit 2) is ≤14 days. Visit 1 (Screening) and Visit 2 can occur during the hospitalization, ER visit, physician’s office visit, and up to 14 days afterward. 2. Duration of subjects’ participation in study is 29 weeks (completing subjects), approximately (unless subject is prematurely withdrawn from the study). ER: Emergency Room; F/U: Follow-up; TC: Telephone call; V: Visit; Wks: Weeks.