[1] Brown Univ, Sch Publ Hlth, Dept Biostat, Ctr Stat Sci, Providence, RI 02912 USA
[2] Brown Univ, Dept Emergency Med, Alpert Med Sch, Providence, RI 02912 USA
[3] Brown Univ, Sch Publ Hlth, Dept Epidemiol, Providence, RI 02912 USA
[4] Univ Massachusetts, Sch Med, Dept Quantitat Hlth Sci, Worcester, MA USA
[5] Univ Massachusetts, Sch Med, Ctr Hlth Policy & Res, Worcester, MA USA
[6] Penn State Univ, Dept Biobehav Hlth, University Pk, PA 16802 USA
[7] Univ Penn, Sch Nursing, Dept Family & Community Hlth, Philadelphia, PA 19104 USA
[8] Fenway Community Hlth, Boston, MA USA