The National Hospital Ambulatory Medical Care Survey (NHAMCS) is a national survey that collects information information about the provision and use of ambulatory medical care services in the United States. The survey samples visits to hospital outpatient departments (OPD), hospital emergency departments (ED), and hospital-based ambulatory surgery locations (ASL). The survey has been conducted annually since 1992; since 2018, the survey has only collected data on hospital emergency department visits.

Approximately 500 nationally representative hospitals are selected to provide data on a sample of patient visits each year. Excluded hospitals include federal, hospital units within institutions, and hospitals with fewer than six staffed beds for patient use. Data collected includes patient demographics, conditions treated, services provided, and payment methods. The data is weighted to produce national estimates.

The National Hospital Ambulatory Medical Care Survey (NHAMCS) has been fielded annually since 1992 to collect data on the utilization and provision of ambulatory care services in hospital emergency and outpatient departments. Data collection from hospital-based ambulatory surgery centers began in 2009. And between 2010 and 2012 NHAMCS gathered data on visits to freestanding ambulatory surgery centers. In 2018, the survey began focusing on just the ambulatory visits made to emergency departments. Each emergency department is randomly assigned to a 4-week reporting period. During this period, data for a systematic random sample of visits are recorded by Census interviewers using a computerized Patient Record Form. Data are obtained on patient characteristics such as age, sex, race, and ethnicity, and visit characteristics such as patient’s reason for visit, provider’s diagnosis, services ordered or provided, and treatments, including medication therapy. In addition, data about the facility are collected as part of a survey induction interview.

List of footnotes, notes, and source information for The National Hospital Ambulatory Medical Care Survey (NHAMCS). Each row of this dataset contains the accompanying text for a footnote found in NHAMCS dataset. The footnote lookup can be merged onto any NHAMCS dataset using, DATASET_SHORT_NAME, FN_ID, FN_TYPE, and FN_TEXT.

SOURCE: National Center for Health Statistics CDC, The National Hospital Ambulatory Medical Care Survey (NHAMCS)

The NHAMCS provides data from samples of patient records selected from emergency departments (EDs) and outpatient departments (OPDs) of a national sample of hospitals. The resulting national estimates describe the use of hospital ambulatory medical care services in the United States. For the 1998 survey, data were collected from 239 OPDs and 398 EDs. Among the variables included are age, race, and sex of the patient, reason for the visit, physician's diagnoses, cause of injury (ED only), surgical procedures (OPD only), medication therapy, and expected source of payment.

The National Hospital Ambulatory Medical Care Survey (NHAMCS) is designed to collect data on the utilization and provision of ambulatory care services in hospital emergency (ED) and outpatient (OPD) departments. Annual data collection began in 1992. Data are obtained on demographic characteristics of patients, expected source(s) of payment, patients' complaints, physicians' diagnoses, diagnostic/screening services, procedures, medication therapy, disposition, types of health care professional s seen, causes of injury where applicable, and certain characteristics of the hospital, such as type of ownership. Data are accessible through the SETS 2.0 retrieval software on the CD-ROM.

The National Hospital Ambulatory Medical Care Survey (NHAMCS) has been fielded annually since 1992 to collect data on the utilization and provision of ambulatory care services in hospital emergency and outpatient departments. Data collection from hospital-based ambulatory surgery centers began in 2009. And between 2010 and 2012 NHAMCS gathered data on visits to freestanding ambulatory surgery centers. In 2018, the survey began focusing on just the ambulatory visits made to emergency departments. Each emergency department is randomly assigned to a 4-week reporting period. During this period, data for a systematic random sample of visits are recorded by Census interviewers using a computerized Patient Record Form. Data are obtained on patient characteristics such as age, sex, race, and ethnicity, and visit characteristics such as patient’s reason for visit, provider’s diagnosis, services ordered or provided, and treatments, including medication therapy. In addition, data about the facility are collected as part of a survey induction interview.

NHAMCS is an annual survey of emergency department visits.;SAS programs are required to read this data.

Abstract (en): The National Hospital Ambulatory Medical Care Survey (NHAMCS) was inaugurated in 1992 to fill a gap in data about ambulatory medical care in the United States. Although the National Ambulatory Medical Care Survey (NAMCS) collects annual data on patient visits to physician offices, it excludes the hospital emergency room and outpatient department visits that make up a large part of the total ambulatory care received each year. The NHAMCS provides data from samples of patient records selected from emergency departments (EDs) and outpatient departments (OPDs) of a national sample of hospitals. The resulting national estimates describe the use of hospital ambulatory medical care services in the United States. For the 1996 survey, data were collected from 235 OPDs and 392 EDs. Among the variables included are age, race, and sex of the patient, reason for the visit, physician's diagnoses, cause of injury (ED only), surgical procedures (OPD only), medication therapy, and expected source of payment. 2006-01-18 File CB2365.ALL was removed from any previous datasets and flagged as a study-level file, so that it will accompany all downloads. (1) This collection has not been processed by ICPSR staff. ICPSR is distributing the data and documentation for this collection in essentially the same form in which they were received. When appropriate, hardcopy documentation has been converted to machine-readable form and variables have been recoded to ensure respondents' anonymity. (2) Per agreement with NCHS, ICPSR distributes the data file(s) and technical documentation in this collection in their original form as prepared by NCHS.

The National Hospital Ambulatory Medical Care Survey (NHAMCS) is designed to collect data on the utilization and provision of ambulatory care services in hospital emergency and outpatient departments and in ambulatory surgery centers. Hospital-based ambulatory surgery centers were first added to this study in 2009, and freestanding ambulatory surgery centers were added in 2010.

The National Hospital Ambulatory Medical Care Survey (NHAMCS), conducted by the National Center for Health Statistics (NCHS), collects annual data on visits to emergency departments to describe patterns of utilization and provision of ambulatory care delivery in the United States. Data are collected from nonfederal, general, and short-stay hospitals from all 50 U.S. states and the District of Columbia, and are used to develop nationally representative estimates. The data include counts and rates of emergency department visits from 2016-2022 for the 10 leading primary diagnoses and reasons for visit, stratified by selected patient and hospital characteristics. Rankings for the 10 leading categories were identified using weighted data from 2022 and were then assessed in prior years.

*Ethnicity missing for 4.7% of sample.†MSA: Metropolitan Statistical Area.‡NA: Not applicable due to the sample size of interest in the surveys was less than 30, as the estimate is considered unreliable under NAMCS and NHAMCS analysis recommendations.