National Hospital Ambulatory Medical Care Survey (NHAMCS)
Study Number	S15_9201
Background of Dataset
Purpose of the Data Set	Provides information annually on the use of ambulatory medical care services provided by hospitals in the United States, such as patient symptoms, demographic characteristics, diagnoses, services provided, drugs prescribed and referral status.
Criteria(s) for Inclusion/Exclusion
Age Range Included
Method(s) of Data Gathering	Each participating hospital provides information on target sample of 50 emergency department visits and 150 outpatient department visits during a 4-week period. Using an encounter form a national sample of 524 non-Federal, short stay or general hospitals, or approximately 8% of the universe.
Sampling Frame/Design
Limitation(s) of Study	About 8% of the encounter forms do not have race reported and 15% do not have ethnicity.
Year(s) Available	1992-Present.
Number of Observations	Approx. 71,000 annually.
Unit of Observation	A visit.
Publisher	National Center for Health Statistics (NCHS), CDC
Contact Information/Web Address	http://www.cdc.gov/nchs/
Condition of Use	Publicly Available.
Contents of Database
Key Linking Variables
•Patient identifier
•Physician identifier
•Health facility identifier
•Geographic identifier
•Other identifier
Demographics Information
•Sex	Yes.
•Race	Yes.
•Geographic location
•Income
•Education
•Employment status
•Others
Access/Utilization Information
Unit of Utilization
Source of Information
•Self reported
•Parent
•Medical provider
•Billing/encounters	Yes.
•Other source
Health Insurance Information
•Insurance status
•Insurance type
•Other information
Health Care Utilization
>Type
1) Outpatient	Yes.
•Date of visits
•Number of visits
•Referrals information	Yes.
•Specialty visits
•Other outpatient utilization	Patient symptoms and diagnosis.
2) Inpatient
•Admission/discharge dates
•Number of admissions
•Length of stay
•Admission status (transfer, ER      admissions...etc)
•Discharge status
•Other information	Patient symptoms and diagnosis.
3) Emergency room	Yes.
•Date of visits
•Number of visits
•Other information
4) Pharmacy
•Date of prescription
•Drug information	Yes.
•Other information
5) Other utilization
•Home care services
•Long term care
•Other services
>Medical Codes
•CPT codes
•ICD-9 codes
•DRG codes
•Other codes
Health Care Facility Information
•Location
•Number of beds
•Number of MDs
•Other information	Information on emergency department visits, and outpatient department visits.
Physician Information
•Specialty
•Name
•License Number
•Other information
Cost/Expenditure Information
•Unit of cost
•Charges/costs/payments
•Total
•Allied and additional services
•Pharmacy
•Out-of-pocket payments
•Other information
Other Information
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