Estadisticas Salud

Number 27 n November 3, 2010

National Ambulatory Medical Care Survey: 2007 Summary
by Chun-Ju Hsiao, Ph.D.; Donald K. Cherry, M.S.; Paul C. Beatty, Ph.D.; and Elizabeth A. Rechtsteiner, M.S., Division of Health Care Statistics

Abstract
Objectives—This report describes ambulatory care visits made to physician offices in the United States. Statistics are presented on selectedcharacteristics of the physician’s practice, the patient, and the visit. Methods—The data presented in this report were collected in the 2007 National Ambulatory Medical Care Survey (NAMCS), a national probability sample survey of visits to nonfederal office-based physicians in the United States. Sample data are weighted to produce annual national estimates of physician visits. Results—During 2007, an estimated994.3 million visits were made to physician offices in the United States, an overall rate of 335.6 visits per 100 persons. About one-third of office visits, 34.9 percent, were made to practices with all or partial electronic medical records systems, while 85.1 percent of the visits were made to practices with all or partial electronic submission of claims. From 1997 to 2007, the percentage ofvisits to physicians who were solo practitioners decreased 21 percent. During the same period, visits to physicians who were part of a group practice with 6–10 physicians increased 46 percent. There were an estimated 106.5 million injury- or poisoning-related office visits in 2007, representing 10.7 percent of all visits. Medications were ordered, supplied, or administered at 727.7 million officevisits, accounting for 73.2 percent of all office visits. In 2007, about 2.3 billion drugs were ordered, supplied, or administered, resulting in an average of 226.3 drug mentions per 100 visits. Keywords: ambulatory care c physician office care c medications c chronic condition

Introduction
The National Ambulatory Medical Care Survey (NAMCS), which began in 1973, was inaugurated to gather,analyze, and disseminate information about health care provided by officebased physicians. NAMCS and the National Hospital Ambulatory Medical Care Survey (NHAMCS) are parts of

the ambulatory component of the National Health Care Surveys, a family of surveys that measure health care utilization across various types of providers. More information about the National Health Care Surveys can be foundat the following website: http://www.cdc.gov/nchs/nhcs.htm. NAMCS and NHAMCS data have been used in articles examining important topics of interest in public health and in health services research. A list of publications is available from http://www.cdc.gov/nchs/data/ahcd/ publist-9-4-2009.pdf. In addition to NAMCS, other reports highlight visits to emergency departments (1) and outpatientdepartments (2). Annual reports are available from http:// www.cdc.gov/nchs/ahcd/ ahcd_reports.htm. Public-use data files are available from http://www.cdc.gov/ nchs/ahcd/ahcd_questionnaires.htm. Data from NAMCS 2007 will also be available on CD ROM. These and other products can be obtained from the NCHS Office of Information Services, Information Dissemination Staff at 1–800–232–4636, the Ambulatory andHospital Care Statistics Branch at 301–458–4600, or by e-mail at CDCINFO@cdc.gov. Ambulatory medical care is the predominant method of providing health

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention National Center for Health Statistics

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National Health Statistics Reports n Number 27 n November 3, 2010 gestational age, health education,and nonmedication treatment. discussion of methodology can be found in the ‘‘Technical Notes.’’ A sample PRF can be found at the end of this report (Figure I). In this report, the determination of statistical inference is based on the two-tailed t-test. The Bonferroni inequality was used to establish the critical value for statistically significant differences (0.05 level of significance) based on...