title: National Hospital Ambulatory Medical Care Survey: 2006 outpatient department summary.
abstract: OBJECTIVE
  This report describes ambulatory care visits to hospital outpatient departments (OPDs) in the United States. Statistics are presented on selected hospital, patient, and visit characteristics. Selected trends in OPD utilization from 1996 through 2006, as well as items new to the 2006 survey, are also presented.
  
  
  METHODS
  The data presented in this report were collected in the 2006 National Hospital Ambulatory Medical Care Survey (NHAMCS), a national probability sample survey of visits to emergency departments (EDs) and OPDs of nonfederal short-stay and general hospitals in the United States. Sample data were weighted to produce annual national estimates.
  
  
  RESULTS
  During 2006, an estimated 102.2 million visits were made to hospital OPDs in the United States, about 34.7 visits per 100 persons. Females had higher OPD visit rates (41.2 per 100 persons) than males (28.0 visits per 100 persons). Black or African-American persons had higher OPD visit rates (63.5 visits per 100 persons) than white persons (31.3 visits per 100 persons). Visit rates to OPD clinics for preventive care were highest for children under 1 year of age (43.2 visits per 100 persons). About one-third of OPD visits (31.1%) were made by patients relying on Medicaid or the State Children's Health Insurance Program (SCHIP). The preventive care visit rate for Medicaid or SCHIP patients (23.3 visits per 100 persons) was almost four or more times higher than for patients using other payment sources (3.5 to 6.0 visits per 100 persons). For the first time since the survey began in 1992, diabetes mellitus was the leading primary diagnosis at OPD visits, ahead of essential hypertension. About one-half of OPD visits (51.4%) were made by patients with one or more comorbid chronic conditions. From 1996-2006, the percentage of visits made by adults aged 18 years and over with chronic diabetes increased by 43%, and visits among adults with hypertension as a chronic condition increased by 51%.
authors.affiliation: Division of Health Care Statistics, Center for Disease Control and Prevention, National Center for Health 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: Jianmin
authors.initials: J
authors.lastname: Xu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D019538:Health Care Surveys / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D038801:International Classification of Diseases / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D055815:Young Adult