Transcript NAMCS and NHAMCS

Mental Health Data from the
NAMCS and NHAMCS
Susan M. Schappert, M.A.
Ambulatory and Hospital Care Statistics Branch
Division of Health Care Statistics
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Centers for Disease Control and Prevention
National Center for Health Statistics
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Topics To Be Covered
• Survey Overview
• Data Collected
• Published Mental Health Research
Using Data from NAMCS and
NHAMCS
• User Considerations
• How to Get the Data
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An Overview of
NAMCS and NHAMCS
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NAMCS and NHAMCS
• National Ambulatory Medical Care
Survey (NAMCS)
– Visits to office-based physicians
• National Hospital Ambulatory
Medical Care Survey (NHAMCS)
– Visits to hospital emergency
and outpatient departments
(EDs and OPDs)
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History of NAMCS
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Planning began in 1967
Inaugurated in 1973
Fielded 1973-1981, 1985, 1989-present
Database covering more than 30 years
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History of NHAMCS
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Planning began in 1976
Inaugurated December 1991
Fielded annually
17th year of operation
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NAMCS Sample Design
• Three stage design
– 112 primary sampling units (counties/groups of
counties)
– Physician practices within PSUs
– Patient visits within practices
• About 3,000 physicians are selected
• Each physician is randomly assigned to a
1-week reporting period
• Data obtained for 25,000-30,000 patient visits
• Sample data must be weighted to produce
national estimates
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Scope of the NAMCS
• Basic unit of sampling is the physicianpatient visit
• In scope visits:
– Must occur in physician’s office
– Must be for medical purposes
– Administrative visits not sampled
– House calls, emails, phone calls not
sampled
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Scope of the NAMCS
• Physicians must be:
– Classified by AMA or AOA as primarily
engaged in office-based patient care
– nonfederally employed;
– not in anesthesiology, radiology, or
pathology
– 59 percent response rate in 2006
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Physicians Sampled in the NAMCS
• Physicians are typically stratified into 15 specialty
groups
– general and family practice, internal medicine, pediatrics,
ob-gyn, general surgery, orthopedic surgery, cardiovascular
diseases, dermatology, urology, psychiatry, neurology,
ophthalmology, otolaryngology, and an “other” category
– 2006 included an additional sample of oncologists, and a
sample of community health centers
– 29,392 Patient Record Forms completed by about 1,400
physicians in 2006
– 570+ primary care physicians (general and family practice,
internal medicine, pediatrics, and ob-gyn) responded in
2006 with data on about 14,400 visits (nearly half of total
visit records)
– 80+ psychiatrists reported on nearly 1,400 visits (4.7% of
total)
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In-Scope NAMCS Locations
• Freestanding clinic/urgicenter
• Federally qualified health center
• Neighborhood and mental health
centers
• Non-federal government clinic
• Family planning clinic
• Health maintenance organization
• Faculty practice plan
• Private solo or group practice
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Out-of-Scope NAMCS Locations
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Hospital ED’s and OPD’s
Ambulatory surgicenter
Institutional setting (schools, prisons)
Industrial outpatient facility
Federal Government operated clinic
Laser vision surgery
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NHAMCS Sample Design
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Multistage probability design
First stage sample of 112 PSUs
Hospitals within PSUs
Clinics within OPDs, ESA (emergency service
area) within EDs
• Patient visits within clinics, ESAs
• 4-week reporting period
• 486 hospitals sampled in 2006; 35,849 ED visits
and 35,105 OPD visits
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Scope of the NHAMCS
• Basic unit of sampling is patient visit
• Emergency and outpatient departments of
noninstitutional general and short-stay
hospitals
• Not Federal, military, or Veterans
Administration facilities
• Located in 50 states and D.C.
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Sampled OPD Clinics
• 6 clinic types are defined and used for sampling:
general medicine, surgery, pediatrics, ob-gyn,
substance abuse, and “other”
• “Other” includes anxiety, behavioral medicine,
eating disorders, psychiatry (adult, child,
pediatric, geriatric), mental health, mental
hygiene, psychopharmacology, and sleep
disorders
• Not included: partial hospitalization programs,
day hospital programs, psychology, methadone
maintenance
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Data Collected in the
NAMCS and NHAMCS
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Data Collection
• U.S. Census Bureau is our field agent
• Induction interview to train medical office or
hospital staff on data collection procedures and
to obtain data on practice or facility
characteristics
• Physician’s office/hospital staff is responsible for
completion of Patient Record forms; Census
abstracts as a last resort. In 2006, more than
one-third of NHAMCS forms and about one-half
of NAMCS forms were completed by Census
abstraction.
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Data Collection
• Patient Record Forms (PRFs)
– Nearly identical for NAMCS and OPD
– Some differences for ED
– Redesigned once every 2 years
– Copies at our website:
www.cdc.gov/nhcs/namcs.htm
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Data Items
• Patient characteristics
– Age, sex, race, ethnicity
• Visit characteristics
– Source of payment, continuity of care,
reason for visit, diagnosis, treatment
• Provider characteristics
– Physician specialty, hospital ownership,
region and urban-rural status, use of
electronic medical records, and much
more
• Drug characteristics added in 1980
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Mental Health Items Collected in
NAMCS and NHAMCS-OPD
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Patient’s reason for visit (all survey years)
Physician’s diagnosis (all survey years)
Does patient now have depression? (1991-92, 1995-96, 2005-06)
Cause of injury (1995-2004), verbatim text added (1997-2004)
Diagnostic/screening services ordered or provided
– Mental status exam (1979-81, 1991-92, 1995-96)
– Depression screening (2005-06)
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Medication therapy (1980-2006)
Non-medication therapy ordered or provided
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Psychotherapy/therapeutic listening (1973-1981)
Psychotherapy (1985-92, 1995-2006)
Psycho-pharmacotherapy (1997-2000)
Alcohol abuse counseling (1991-92)
Drug abuse counseling (1991-92)
Stress management counseling (1991-92, 1997-2000, 2005-06)
Mental health counseling (1995-2000)
Mental health/stress management counseling (2001-04)
Other mental health counseling (2005-06)
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Mental Health Items Collected in
NHAMCS-ED
• Patient’s reason for visit (all survey years), verbatim text added
2005-06
• Physician’s diagnosis (all survey years)
• Does patient now have depression? (1995-96)
• Cause of injury (1995-2006), verbatim text added (1997-2006)
• Intentional injury? (1997-2006)
• Violence-related injury? (1995-96)
• Alcohol- or drug-related visit? (1992-96)
• Alcohol-related visit? (2001-04)
• Adverse drug event (2001-02)
• Patient oriented x 3 (2003-06)
• Medication therapy (all survey years)
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Multiple Response Fields
• Up to 3 reasons for visit, causes of injury,
physician diagnoses can be reported for each
visit (no cause of injury on NAMCS and OPD
starting in 2005)
• Up to 8 medications and each medication can
have up to 3 therapeutic classes and up to 5
ingredients
• Multiple procedure codes for NAMCS and OPD
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Coding Systems Used
• Reason for Visit Classification (NCHS)
• ICD-9-CM for diagnoses, causes of injury,
and procedures
• Drug Classification System (NCHS)
• Multum Lexicon starting with 2006 data
(previously used National Drug Code
Directory)
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Drug Data in NAMCS/ NHAMCS
Respondents may list up to 8 medications (including Rx, or
prescription, and OTC, or over-the-counter, medications,
immunizations, allergy shots, anesthetics, and dietary
supplements) that were ordered, supplied, administered, or
continued during the visit.
Each entry is called a drug mention. Visits with one or
more drug mentions are called drug visits.
Respondents are asked to report trade names or generic
names only (not dosage, administration, or regimen).
Cannot link drugs with diagnosis.
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• NAMCS or NHAMCS drug data can be
analyzed
– at the visit level (for example, the number
of visits at which a particular drug was
prescribed)
– or at the medication level (for example,
the number of “mentions” of a particular
drug at ambulatory care visits
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Published Mental Health Research
Using Data from NAMCS and
NHAMCS
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Hot Topics
• See the NAMCS/NHAMCS website for a complete list of
publications (including journal articles) by NCHS and
others that use our data (about 100 focus on mental
health) – updated monthly
• Mental health research using NAMCS/NHAMCS data
includes:
– visits for specific diagnoses (depression, ADHD [attention
deficit/hyperactivity disorder], and sleep disorders have been
most commonly published, but there are also studies on visits for
anxiety disorders, bipolar disorder, autism, schizophrenia)
– pharmacotherapy (antidepressants, antipsychotics, hypnotics,
stimulants, psychotropics in general)
– mental health care by physicians other than psychiatrists
– racial/ethnic/gender disparities in mental health care
– other topics such as self-harm (ED visits), insurance issues,
substance abuse
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Additional Mental Health Data from
NAMCS and NHAMCS
• Many annual NCHS summary reports (for
example, Health US) include mental health
related data, such as trends in prescribing
antidepressants
• Annual NAMCS and NHAMCS summary reports
can include various mental health-related
statistics (for example, statistics on visits to
psychiatrists within tables by physician specialty)
• Some NCHS reports have focused specifically
on visits to psychiatrists, alcohol/drug related
visits, etc.
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User Considerations
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A few things to keep in mind…
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NAMCS/NHAMCS sample visits, not patients
No estimates of incidence or prevalence
No state-level estimates
We do not sample by setting or by nonphysician providers with one exception:
– Note that, from 2006, NAMCS includes a stratum of
CHCs (community health centers), and non-physician
providers are sampled within CHCs
• May capture different types of care for solo vs.
group practice physicians
• May not have much data in a single year for
less common conditions or events
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NAMCS vs. NHAMCS
• Consider what types of settings are best
for a particular analysis
– Persons of color are more likely to visit OPDs
and EDs than physician offices
– Persons in some age groups make
disproportionately larger shares of visits to
EDs than offices and OPDs
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Ways to Improve Reliability of
Estimates
• Combine NAMCS, ED, and OPD data to
produce ambulatory care visit estimates
• Combine multiple years of data
• Aggregate categories of interest into
broader groups.
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Caveat on Counseling Services
• Diagnostic services are reflected accurately on medical
records, but counseling services may not be
• NAMCS (and OPD) data may underestimate the amount
of health habit counseling that occurs if it is not
documented in the medical record
• These findings were published by in the following article:
Gilchrist VJ, Stange KC, Flocke SA, McCord G,
Bourguet CC. A Comparison of the National Ambulatory
Medical Care Survey (NAMCS) Measurement Approach
With Direct Observation of Outpatient Visits. Medical
Care 42(3), March 2004, 276-280.
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How To Get the Data
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http://www.cdc.gov/nchs/namcs.htm
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Public Use Micro-data Files
• Downloadable files
• NAMCS, 1973-2006
• NHAMCS, 1992-2006
• CD-ROMs
• NAMCS, 1990-2005
• NHAMCS, 1992-2005
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Enhanced Public Use Files
• SAS input statements, label statements,
and format statements (1993-2006)
• SPSS and Stata code for 2002-2006
• Masked sample design variables
– Allow use of SUDAAN, Stata, etc.
– Available for 1993-2006
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NCHS Research Data Center
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Advantages of the NCHS
Research Data Center
• Users gain access to information not
available on public use files
– Patient: ZIP code-linked income, education,
poverty status, percent foreign born, percent not
speaking English well, urban-rural classification
– Provider: physician sex, age, and board
certification, teaching hospital
– Geographic: FIPS (Federal Information
Processing Standard) state and county codes
– Special files and data supplements
– For a complete list of variables, contact the
Ambulatory and Hospital Care Statistics Branch
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Research Data Center – cont.
• Can merge with contextual variables (e.g.,
Area Resource File, National Health Interview
Survey, National Hospital Discharge Survey
Census)
– Health status level
– Health Maintenance Organization (HMO)
penetration
– Physician and specialist supply
– Medicaid reimbursement
– Air quality
– Percent in poverty
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Research Data Center
Procedures
• Submit a proposal
• May not use data to identify patients or
providers or geographic location of
providers
• May not remove data files
• Fees vary based on whether use is
onsite or remote and whether project
requires file construction by NCHS staff
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Research Data Center
• E-mail: [email protected]
• Website: www.cdc.gov/nchs/r&d/rdc.htm
• Call (301) 458-4277
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Additional Information
• Call the Ambulatory and Hospital Care Statistics
Branch at (301) 458-4600
• Visit our website at www.cdc.gov/nhcs/namcs.htm
• Join the ACLIST. It’s a moderated newsgroup for
persons interested in NAMCS/NHAMCS. It currently
consists of about 2,600 subscribers.
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