[1] Denver Hlth Med Ctr, Dept Pediat, 301 W 6th Ave,MC 1911, Denver, CO 80204 USA
[2] Univ Colorado Denver, Dept Biostat & Informat, Sch Publ Hlth, Aurora, CO USA
[3] Univ Colorado Denver, Dept Pediat, Aurora, CO USA
[4] Univ Colorado Denver, Dept Family Med, Aurora, CO USA
[5] Univ Colorado Denver, Dept Pediat Infect Dis, Sch Med, Aurora, CO USA
[6] Adult & Child Consortium Hlth Outcomes Res & Deli, Aurora, CO USA
[7] Kaiser Permanente Colorado, Inst Hlth Res, Denver, CO USA