[1] Univ Penn, Perelman Sch Med, Ctr Emergency Care Policy & Res, Blockley Hall,423 Guardian Dr,Room 413, Philadelphia, PA 19104 USA
[2] Ctr Hlth Econ Treatment Intervent Subst Use Disor, Philadelphia, PA 19104 USA
[3] Leonard Davis Inst Hlth Econ, 3641 Locust Walk, Philadelphia, PA 19104 USA
[4] Drexel Univ, Dornsife Sch Publ Hlth, 3215 Market St, Philadelphia, PA 19104 USA
[5] Weill Cornell Med Coll, 425 East 61st St,Suite 301, New York, NY 10065 USA
[6] Univ Penn, Perelman Sch Med, Dept Family Med & Community Hlth, 3620 Hamilton Walk, Philadelphia, PA 19104 USA