Ambulatory Health Care Data

Ambulatory Care Monthly News

June 2019

  • STATS OF THE MONTH

In recognition of Alzheimer’s & Brain Awareness Month (June 1-30) we present estimates for Alzheimer’s disease and dementia from the 2016 National Ambulatory Medical Care Survey (NAMCS).

  • In 2016, patients with Alzheimer’s disease or dementia documented in the medical record accounted for 0.7% of all office-based physician visits. Visits by patients with Alzheimer’s disease or dementia increased with age. Only 0.4% of visits made by patients aged 45-64 and 0.8% visits made by patients aged 65-74 had Alzheimer’s disease or dementia in the medical record whereas 3.5% of visits made by patients aged 75 and over had Alzheimer’s disease or dementia in the medical record. (Estimates from Table 18 pdf icon[PDF – 793 KB])

In recognition of National Safety Month (June 1-30) we present estimates for injury visits to emergency departments (ED), from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • In 2016, injury visits accounted for 29.0% of all ED visits. There were approximately 42 million injury visits to the ED representing a rate of 13.3 visits per 100 persons. Visit rates by Black or African American persons were higher than visit rates by White persons (20.4 versus 13.1 visits per 100 persons). (Estimates from Table 15 pdf icon[PDF – 738 KB])
  • DATA TIP OF THE MONTH

Did you know…

NAMCS and NHAMCS are national probability sample surveys that use stratified, multistage sampling designs.  That is, visits are always clustered within providers and providers are sometimes clustered within geographic primary sampling units.  The sampling design affects the standard errors of estimates based on data collected from the sample.  Therefore, data users should always calculate standard errors for the survey estimates using statistical software that takes the complex sampling design into account.  Such software includes SUDAAN, SAS (SURVEYFREQ and SURVEYMEANS procedures), Stata, and SPSS Complex Samples, among others. Make sure all of the sample records – and not just those in a subset of the sample – are included in the analysis in order to obtain the best variance estimates.  This can be accomplished with a SUBPOPN statement in SUDAAN, or by using the DOMAIN statement in SAS, for example.

  • DATA TELL STORIES 

Tell Us Yours! How have you used information from the National Ambulatory Medical Care Survey or the National Hospital Ambulatory Medical Care Survey? Email us a brief description. In the subject field of your email, write “My NAMCS/NHAMCS data use example”. Your examples will help us showcase the value of NAMCS and NHAMCS.

 

May 2019

  • STATS OF THE MONTH

In recognition of National Osteoporosis Month (May 1-31)  we present estimates for osteoporosis from the 2016 National Ambulatory Medical Care Survey (NAMCS).

  • In 2016, adult patients with osteoporosis documented in the medical record accounted for 3.0% of all office-based physician visits made by adults. Visits by patients with osteoporosis differ by sex. 4.3% of visits made by adult women had osteoporosis in the medical record whereas 1.1% of visits made by adult men had osteoporosis in the medical record. (Estimates from the Public Use File)

In recognition of National Stroke Awareness Month (May 1-31), we present estimates for visits to emergency departments (ED) for cerebrovascular disease or history of stroke or transient ischemic attack, from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • In 2016, patients with cerebrovascular disease or history of stroke or transient ischemic attack (CVA) documented in the medical record accounted for 3.2% of all visits made to the ED. Visits by patients with CVA increased with age. 1.5% of visits made by patients aged 18-54 had CVA in the medical record whereas 5.4% of visits made by patients aged 55-64 and 11.6% visits made  by patients aged 65 and over had CVA in the medical record. (Estimates from Table 13 pdf icon[PDF – 740 KB] and the Public Use File)
  • DATA TIP OF THE MONTH

Did you know…

In 2005, data for the initial visit to ED (EPISODE=1) was not collected. For researchers interested in the episode of care for visits in 2005, an imputed variable (INITVIS; included in the 2005 public use file) was created based on a regression model-based imputation strategy using data from 2003-04. It should be noted that because this is an imputed variable, it is not comparable to the EPISODE variable from other years (starting in 2001) and should be used with caution when conducting any year-to-year trend analysis. More information on the methodology and limitations of the imputation model can be found here pdf icon[PDF – 37 KB].

  • NEW PRODUCTS RELEASED THIS MONTH
    • 2016 NAMCS SUMMARY WEB TABLES pdf icon[PDF – 793 KB] – The Ambulatory and Hospital Care Statistics Branch is pleased to release the most current nationally representative data on ambulatory care visits to physician offices in the United States. Estimates are presented on selected physician, patient, and visit characteristics using data collected in the 2016 NAMCS.
  • DATA TELL STORIES

Tell Us Yours! How have you used information from the National Ambulatory Medical Care Survey or the National Hospital Ambulatory Medical Care Survey? Email us a brief description. In the subject field of your email, write “My NAMCS/NHAMCS data use example”. Your examples will help us showcase the value of NAMCS and NHAMCS.

 

April 2019

  • STATS OF THE MONTH

In recognition of World Health Day (April 7)  we present estimates for preventive visits from the 2016 National Ambulatory Medical Care Survey (NAMCS).

  • From NAMCS: In 2016, preventive care was the major reason for visit in 23.1% of all office-based physician visits. Preventive visits made by patients aged 0-18  and by patients aged 19-44 were 31.4 % and 32% of all office-based physician visits, higher than the percentage of preventive visits made by patients aged 45-64 (17.7%) and by patients aged 65 and over (14.5%). (Estimates from the Public Use File)

In recognition of Alcohol Awareness Month (April 1-30), we present estimates for visits to emergency departments (ED) for alcohol-related problems, from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • From NHAMCS: In 2016, alcohol-related problems* were a reason for visit for 1.6% of all ED visits made by adolescents and adults aged 13 and over, with a higher percentage of visits made by males (2.4%) than females (1%). (Estimates from the Public Use File)
    * alcohol related problems (1145.0); alcoholism (2320.0); adverse effect of alcohol (5915.0); alcohol poisoning (5916.0) indicated by patients as any reason for visit. Based on A Reason for Visit Classification (RVC) for Ambulatory Care, National Center for Health Statistics. Vital Health Stat 2(78) 1979
  • DATA TIP OF THE MONTH

Did you know…

Beginning with the 2002 public use files, two new masked design variables were added to the file, for use with statistical software that assumes a single stage of sampling. Data users who wish to combine years of data from 2002 and beyond with years prior to 2002 need to create these two masked design variables for data file years prior to 2002. A technical paper gives instructions on how to do this, and is available here pdf icon[PDF – 34 KB].

  • NEW PRODUCTS RELEASED THIS MONTH
    • 2016 NHAMCS EMERGENCY DEPARTMENT SUMMARY WEB TABLES pdf icon[PDF – 738 KB] – The Ambulatory and Hospital Care Statistics Branch is pleased to release the most current nationally representative data on ambulatory care visits to hospital emergency departments (ED) in the United States. Estimates are presented on selected hospital, patient, and visit characteristics using data collected in the 2016 NHAMCS.
    • An updated 2014 NAMCS Public Use Data File is now available, which corrects the ‘new’ or ‘continued’ status of reported medications. Due to a data processing issue, these items were often set to missing instead of to a new or continued status. The revision affects the variables NCMED1-NCMED30, NUMNEW and NUMCONT. Pre-made SAS, SPSS, and Stata datasets have also been recreated.
    • New pre-made SPSS datasets for NHAMCS 2002-2014 are now available for downloading here.
    • Akinbami LJ, Salo PM, Cloutier MM, Wilkerson JC, Elward KS, Mazurek JM, Williams S, Zeldin DC.  Primary care clinician adherence with asthma guidelines: the National Asthma Survey of Physiciansexternal icon.  J Asthma. 2019 Mar 1:1-13. This article examines adherence to asthma guidelines by using the 2012 National Asthma Survey of Physicians (NAS): a one-time provider questionnaire supplement to National Ambulatory Medical Care Survey (NAMCS). The authors found that pediatricians were more likely to report high adherence than other clinicians and adherence was higher for history-taking recommendations and lower for recommendations involving patient education, equipment and expertise.

 

March 2019

  • STATS OF THE MONTH

In recognition of American Diabetes Alert Day (March 26)  we present estimates for diabetes from the 2016 National Ambulatory Medical Care Survey (NAMCS).

  • From NAMCS: In 2016, adults patients with diabetes* documented in the medical record accounted for 14.3% of all office-based physician visits made by adults. Visits by patients with diabetes increased with age. 2.9% of visits made by patients aged 18-44  had diabetes in the medical record whereas 16.2% of visits made by patients aged 45-64 and 22.5% visits made by patients aged 65 and over had diabetes in the medical record. (Estimates from the Public Use File)
    *includes both Type I diabetes mellitus (insulin dependent or IDDM), Type II diabetes mellitus (non-insulin dependent or NIDDM), and diabetes with type unspecified.

In recognition of National Kidney Month (March 1-31), we present estimates for visits to emergency departments (ED) for Chronic Kidney Disease (CKD), from the 2015-2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • From NHAMCS: In 2015 and 2016, visits made by adults with CKD in the medical record accounted for 3.5% of all visits made to the ED. The percentage of visits made by adults with CKD varied by sex. 4.1% of visits made by men had CKD in the medical record whereas 2.7% of visits made by women had CKD in the medical record. A higher percentage of visits were made by non-Hispanic black men with CKD than women (5.0% compared with 2.4%). No difference in ED visits by sex for Hispanic and non-Hispanic white adults was found. (National Hospital Ambulatory Medical Care Survey, 2015–2016. MMWR Morb Mortal Wkly Rep 2019;68:23)
  • DATA TIP OF THE MONTH

Did you know…

The method of collecting payment data in NAMCS/NHAMCS 2005-2007 was different than survey years 2008-present. In 2005-2007 (2005 was the first year that allowed collection of multiple expected sources of payment per visit), beneficiaries of both Medicare and Medicaid (dual eligibles) were assigned Medicaid as the primary expected source of payment (PAYTYPE); from 2008-present, dual eligibles were assigned Medicare as the primary source (PAYTYPER) based on research and analysis which determined that the Medicaid-dominant hierarchy is inconsistent with insurance industry practices. Therefore, when analyzing trends across these two time periods, researchers should keep in mind that two different methods were used to collect payment data. More information can be found in this document pdf icon[PDF – 43 KB] and the 2008 public use file documentation pdf icon[PDF – 1.4 MB].

  • NEW PRODUCTS RELEASED THIS MONTH
    • New pre-made SPSS datasets for NAMCS 2002-2014 are now available for downloading here.
    • For NHAMCS-OPD 2002-2003, corrected Stata code to be used with ASCII data to create Stata datasets, along with pre-made Stata datasets, are available for downloading here.

 

February 2019

  • STATS OF THE MONTH

In recognition of Low Vision Awareness Month (February 1-28) we present estimates for retinal/eye exam ordered or provided from the 2016 National Ambulatory Medical Care Survey (NAMCS).

  • From NAMCS: In 2016, retinal/eye exam was ordered or provided in 13.6% of all office-based physician visits made by adults aged 18 and over. The percentages of visits in which retinal/eye exam was ordered or provided increased with age. Only 7.1% of visits made by patients aged 18-34 had an eye/retinal exam ordered or provided whereas 12.4% of the visits made by patients aged 35-64 and 18.9% of visits made by patients aged 65 and over had a retinal/eye exam ordered or provided. (Estimates from the Public Use File)

In recognition of American Heart Month (February 1-28), we present estimates for visits to emergency departments (ED) for chest pain and related symptoms, from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • From NHAMCS: In 2016, chest pain and related symptoms was the primary reason for visit in 6.4% of all visits to the emergency department (ED) made by adults aged 18 and over. Visits with chest pain and related symptoms as primary reason for visit were higher among patients aged 55 and over (7.5%) than among patients aged 18-54 (5.7%). (Estimates from the Public Use File)
  • DATA TIP OF THE MONTH

Did you know…

A template for producing the Methods section of a journal article using NHAMCS data is available on the Ambulatory Health Care Data website and is linked here pdf icon[PDF – 27 KB].

  • NEW PRODUCTS RELEASED THIS MONTH
    • We are pleased to announce the 2016 NAMCS public use data file and documentation are now available for downloading, along with SAS, Stata and SPSS files.
    • Ashman JJ, Rui P, Okeyode T. Characteristics of office-based physician visits, 2016. NCHS Data Brief, no 331. Hyattsville, MD: National Center for Health Statistics. 2019. This report examines visit rates by age and sex. It also examines visit characteristics—including insurance status, reason for visit, and services—by age. For example, in 2016, there were an estimated 278 office-based physician visits per 100 persons.  The visit rate among females exceeded the rate for males, and the rates for both infants and older adults exceeded the rates for those aged 1–64 years.
    • QuickStats: Percentage of Emergency Department (ED) Visits Made by Patients with Chronic Kidney Disease Among Persons Aged ≥18 Years, by Race/Ethnicity and Sex — National Hospital Ambulatory Medical Care Survey, 2015–2016. MMWR Morb Mortal Wkly Rep 2019;68:23. This QuickStats shows that during 2015-2016, a higher percentage of visits to the ED were made by adult men with chronic kidney disease than women. Same pattern was observed for non-Hispanic black men and women but not for Hispanic and non-Hispanic white adults.
    • NOTICE: A new version of the 2016 NHAMCS Emergency Department public use file was uploaded in January.  This version modifies the formatting for various diagnosis codes (DIAG1-DIAG5; HDDIAG1-HDDIAG5).  The earlier version contained codes which were incorrectly aggregated to a broader category within the same diagnosis group. New versions of the pre-made SAS, Stata, and SPSS files have also been uploaded. More information is available on the Ambulatory Health Care Data website.

 

January 2019

  • STATS OF THE MONTH

In recognition of Cervical Health Awareness Month (January 1-31) we present estimates for Pap test ordered or provided from the 2015 National Ambulatory Medical Care Survey (NAMCS).

  • From NAMCS: In 2015, Pap test was ordered or provided in 4.9% of all office-based physician visits made by females. The percentage of visits made by females in which Pap test was ordered or provided was higher among physicians in metropolitan areas (5.0%) than nonmetropolitan areas (2.5%). (Estimates from Table 21 pdf icon[PDF – 785 KB] and the Public Use File)

In recognition of National Drug and Alcohol Facts Week (January 22–27), we present estimates for visits to emergency departments (ED) for Drug and Alcohol-related problems, from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • From NHAMCS: In 2016, Drug and Alcohol-related problems* were the primary reason for visit for approximately 1.6 million visits to the emergency department (ED) representing 1.1% of all the visits to the ED.  Visits made by males were higher than visits made by females (1.7% versus 0.6%). (Estimates from the Public Use File)
    *refer to alcohol related problem, alcoholism, adverse effect of alcohol, alcohol poisoning, abnormal drug usage, drug addiction, drug dependence, intoxication with drugs, overdose unintentional, substance abuse NOS
  • DATA TIP OF THE MONTH

Did you know…

When examining trends and/or combining multiple years of data, it is important to check that the variables of interest were collected in all of the years contained in your analysis and that the wording of the item and/or answer categories did not change in a way that might impact the analysis. NCHS staff make every effort to point out important changes in the annual public use file documentation, both in the summary of changes at the beginning of the document and in the codebook section.

  • COMING SOON
    • The 2016 National Ambulatory Medical Care Survey Public Use Data File and Documentation are expected to be released later this month.  Please check the Ambulatory Health Care Data website’s What’s New page in a few weeks.
    • Ashman JJ, Rui P, Okeyode T. Characteristics of office-based physician visits, 2016. NCHS Data Brief, no. 331. Hyattsville, MD: National Center for Health Statistics. 2019.  Expected release date: January 23, 2019.

 

December 2018

  • STATS OF THE MONTH

In recognition of National Influenza Vaccination Week (December 4-11), we present estimates for influenza vaccination from the 2015 National Ambulatory Medical Care Survey (NAMCS).

  • From NAMCS: In 2015, influenza vaccination was administered or prescribed in 2.3% of all office-based physician visits. Influenza vaccination was administered or prescribed in 4.9% of the visits made by patients younger than 18, whereas it was administered or prescribed in only 1.9% of the visits made by adults aged 18 and older.

In recognition of World AIDS Day (December 1), we present estimates for visits to emergency departments (ED) made by patients with HIV/AIDS documented in the medical record, from the 2016 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  • From NHAMCS: In 2016, there were an estimated 726,000 visits made to the ED by patients with HIV/AIDS documented in the medical record, representing 0.5% of all visits to the ED. Males with HIV/AIDS documented in their medical records accounted for 0.8% of all ED visits made by males. Females with HIV/AIDS documented in their medical records accounted for 0.3% of all ED visits made by females.

These statistics can be produced using NAMCS and NHAMCS Public Use Datasets and Documentation.

  • DATA TIP OF THE MONTH

Did you know…

When examining trends and/or combining multiple years of data, it is important to check that the variables of interest were collected in all of the years contained in your analysis and that the wording of the item and/or answer categories did not change in a way that might impact the analysis. NCHS staff make every effort to point out important changes in the annual public use file documentation, both in the summary of changes at the beginning of the document and in the codebook section.

 

November 2018

  • STATS OF THE MONTH

In recognition of U.S. Antibiotic Awareness Week (November 13-19), we present estimates on antimicrobial use for acute viral upper respiratory tract infection at emergency department (ED) visits from the 2008-2015 National Hospital Ambulatory Medical Care Survey (NHAMCS).

  •  From 2008–2011 to 2012–2015, the percentage of visits for acute viral upper respiratory tract infection that had an antimicrobial ordered or prescribed decreased from 37.1% to 25.5% among emergency departments (EDs) located in nonmetropolitan statistical areas, but this decline was not seen among EDs in metropolitan statistical areas. (Antimicrobials is a more general drug category that includes antibiotics.) http://dx.doi.org/10.15585/mmwr.mm6703a7external icon

In recognition of Chronic Obstructive Pulmonary disease (COPD) Awareness Month (November 1-30), we present estimates for COPD from the 2015 National Ambulatory Medical Care Survey (NAMCS).

  • In 2015, patients with COPD documented in the medical record accounted for 3.2% of all office-based physician visits. Visits by patients with COPD increased with age. Only 0.5% of visits made by patients under age 45 and 2.8% of visits made by patients age 45-64 had COPD, whereas 6.8% of visits made by patients 65-74 years and 7.4 % visits made by patients 75 years and older had COPD in the medical record. (Table 19 NAMCS pdf icon[PDF – 785 KB])
  • DATA TIP OF THE MONTH

Did you know…

For 2012, estimates of visits to all providers (traditional NAMCS physicians and providers sampled within Community Health Center pdf icon[CHC] strata) can be derived by combining physician data from the 2012 traditional NAMCS public use file with provider data from the 2012 NAMCS CHC public use data file. [PDF – 982 KB] New variables available only on the CHC public use file include type of CHC sampled provider (physician, nurse practitioner, physician assistant, or nurse midwife) and imputed time spent with non-physician clinician.

  • NEW PRODUCTS RELEASED THIS MONTH

2016 NHAMCS Emergency Department Public Use Data File and Documentation are now available.

 

October 2018

  • STATS OF THE MONTH

In recognition of National Breast Cancer Awareness Month (October 1-31), we present estimates for breast examination and mammography from the 2015 National Ambulatory Medical Care Survey (NAMCS). In 2015, breast examination and screening was ordered or provided in 6.0% of all office-based physician visits made by females. Mammography was ordered or provided in 3.8% of all office-based physician visits made by females. (Table 21 pdf icon[PDF – 785 KB])

In recognition of Eye Injury Prevention Month (October 1-31), we present estimates for eye injury from the 2015 National Hospital Ambulatory Medical Care Survey (NHAMCS). In 2015, there were an estimated 473,000 emergency department (ED) visits by patients with eye injury, representing 1.2% of the injury visits made to the ED. (Table 18 pdf icon[PDF – 676])

  • DATA TIP OF THE MONTH

Did you know…

NAMCS and NHAMCS data can be used to estimate annual visit rates per unit of population (e.g., per 1,000 population) by dividing the number of visits by the population denominator of interest. Using rates removes the influence of different population sizes (e.g., for adults aged 65-74 and 75+) so that data can be compared across these groups. (2015 NAMCS Public Use File Documentation pdf icon[PDF – 1.6 MB])

  • NEW PUBLICATIONS RELEASED THIS MONTH

There aren’t any new publications this month, but check out our Survey Results and Products page for a listing of all NAMCS and NHAMCS publications.

 

September 2018

  • STATS OF THE MONTH

In recognition of National Recovery Month (September 1-30) we present estimates for substance abuse or dependence from the 2015 National Ambulatory Medical Care Survey (NAMCS). In 2015, patients with substance abuse or dependence documented in their medical record accounted for 2.3% of all office-based physician visits. Visits by patients with substance abuse or dependence were higher for males (3.0% of visits) than females (1.8% of visits) (Table 19 pdf icon[PDF – 785 KB]).

In recognition of National Traumatic Brain Injury Awareness Month (September 1-30) we present estimates for traumatic brain injury visits from the 2015 National Hospital Ambulatory Medical Care Survey (NHAMCS). In 2015, there we an estimated 556,000 emergency department (ED) visits by patients with traumatic brain injury, representing 1.4% of the injury visits made to the ED (Table 18 pdf icon[PDF – 676 KB]).

  • DATA TIP OF THE MONTH

Did you know…

Estimates and standard errors of drug mentions can be obtained by creating a new weight variable (e.g., DRUGWT) by multiplying PATWT (the patient visit weight) by NUMMED (the number of medications recorded at the visit) or DRUGWT=PATWT*NUMMED. DRUGWT can then be used in place of PATWT to produce the estimated number of drug mentions rather than visits. (2015 NAMCS Public Use File Documentation pdf icon[PDF – 1.6 MB])

  • NEW PUBLICATION RELEASED THIS MONTH

Yang NS, Ward BW, Cummings NA. Patient health information shared electronically by office-based physicians: United States, 2015 pdf icon[PDF – 311 KB]. This report provides the first national estimates for types of PHI that are electronically sent, received, integrated, and searched for by physicians with EHR systems, and could be used as a benchmark for future studies.

 

August 2018

  • STAT OF THE MONTH

In recognition of Children’s Eye Health and Safety Month (August 1-31), we present estimates for retinal or eye examination and screening from the 2015 National Ambulatory Medical Care Survey (NAMCS). In 2015, retinal or eye examinations and screenings were provided or ordered in approximately 31 million visits made by patients age 0-17, representing 21% of all office-based physician visits made by patients age 0-17. The percentage of visits in which retinal or eye examinations and screenings were provided or ordered was higher among children age 0-12 (23%) than among adolescents age 13-17 (13%). (Table 21 pdf icon[PDF – 785 KB])

  • DATA TIP OF THE MONTH

Did you know…

The NAMCS and NHAMCS datasets that are available to approved users of the NCHS Research Data Center contain additional variables not included on the public use datasets.

  • NEW PUBLICATIONS THIS MONTH

There aren’t any new publications this month, but check out our Survey Results and Products page for a listing of all NAMCS and NHAMCS publications.

Page last reviewed: June 17, 2019