title: National Hospital Ambulatory Medical Care Survey: 2007 outpatient department summary.
authors.affiliation: Centers for Disease Control and Prevention, National Center for Health Statistics, Division of Health Care Statistics, Hyattsville, MD 20782, USA.
authors.forename: Esther
authors.initials: E
authors.lastname: Hing
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: Hall
authors.forename: Jill J
authors.initials: JJ
authors.lastname: Ashman
authors.forename: Jianmin
authors.initials: J
authors.lastname: Xu