|Dataset Full Name||National Ambulatory Medical Care Survey|
The National Center for Health Statistics conducts the National Ambulatory Medical Care Survey (NAMCS) to measure the health care utilization and delivery of ambulatory services across various providers in the U.S. The NAMCS is based on a sample of patient visits to a representitive sample of non-federal employed office-based physicians primarily engaged in direct patient care. The physician/office survey collects a wide variety of information at the physician/office level while the patient data includes detailed information regarding reason for visit, vital signs, diagnosis and treatments.
NAMCS does not include visits to hospital emergency departments, outpatient departments, department of veterans affairs, occupational health clinics, and institutional clinics. A separate sample of community health centers (CHCs) was added to the survey in 2006.
|Key Terms||Ambulatory, CDC, Physician visit, Statistics, Survey, Physician office|
Centers for Disease Control and Prevention (CDC)
National Center for Health Statistics (NCHS)
|Health Conditions/Disability Measures|
Alzheimer's/dementia, Anxiety disorders, Arthritis,Blood disorder, Body mass index (BMI)/obesity, Cancer, Cardiovascular conditions, Depression, Diabetes, Heart attack, ICD-9/10 diagnostic codes, Infectious diseases, Kidney/renal condition, Osteoporosis,Pulmonary disorders, Stroke
|Disability Measures||NA||Measures/Outcomes of Interest|
|Topics||Physician practice characteristics and specialty, Patient characteristics, Reason for visit, Medical providers seen, Time provider spent with patient, Continuity of care, Primary diagnosis at visit, Comorbid conditions, Vital signs, Diagnostic/screening services, Immunizations, Medications, demographic and regional information, non-medication treatments and proceedures performed/provided, Stage of cancer, Laboratory test results, Health education ordered or provided at visit||Sample|
|Sample Population||Non-federally employed office-based physicians practices and patient visits|
|Sample Size/Notes||2014: 2,179 physicians submitted at data on at least one sampled patient for a total of 45,710 Patient Record forms (PRFs)|
|Unit of Observation||Patient (Physician-patient interaction or visit)|
|Geographic specificity||Region||Data Collection|
|Data Collection Mode||Survey; from 2013 onward, an automated tool collects Patient Record Form (PRF) content (Census Field Representative abstraction or from physician/office staff)|
|Years Collected||1973-1981, 1985, 1989-present|
|Data Collection Frequency||Annual||Strengths and Limitations|
|Strengths||The data include weights designed to produce national estimates of ambulatory medical care services in the U.S. Detailed information regarding patient reason for visit, diagnosis, vital signs, treatments, and medications. Data can be used to measure health care utilization across various types of providers.|
Only includes office visits. Federally employed physicians as well as those practicing in the specialties of anesthesiology, pathology, and radiology are excluded from the sample.
Reporting biases due to non-response and incomplete response (physician response/participation rate in 2014 was 54.8% of those found eligible, but only 36.8% provided data for at least one sampled visit). Approximately 29.7% of race and 25.2% of ethnicity data were missing in 2014.
|Data Access Requirements||
Public Use Dataset
Data use agreement, $ Cost (NAMCS restricted data)
NAMCS web tables:
1973-1991: patient visit data file, and a drug mention data file (in 1991, these two files are linkable)
1992-2011: a single file containing patient visit and drug mention data information
2012 onward: a single file containing patient visit and drug mention data, as well as a separate file of data for CHCs NAMCS restricted data (additional information and variables masked in the publicly available NAMCS public use microdata files)
NAMCS publication list:
NAMCS Micro-data file documentation:
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Acknowledgements: This tool was developed through the efforts of William Erickson and Arun Karpur, and web designers Jason Criss and Jeff Trondsen at Cornell University. Many thanks to graduate students Kyoung Jo Oh and Yeong Joon Yoon who developed much of the content used in this tool.
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