Analyzing nchs drug data nhanes and n hamcs
Download
1 / 27

Analyzing NCHS Drug Data: NHANES and N/HAMCS - PowerPoint PPT Presentation


  • 86 Views
  • Uploaded on

Analyzing NCHS Drug Data: NHANES and N/HAMCS. Amy B. Bernstein, Sc.D. Presented at the AcademyHealth Annual Research Meeting San Diego, California June 6, 2004. National Center for Health Statistics. Topics. Definition of “drug” Issues in drug utilization analyses Coding issues

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Analyzing NCHS Drug Data: NHANES and N/HAMCS' - danno


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Analyzing nchs drug data nhanes and n hamcs

Analyzing NCHS Drug Data: NHANES and N/HAMCS

Amy B. Bernstein, Sc.D.

Presented at the AcademyHealth Annual Research Meeting

San Diego, California

June 6, 2004

National Center for Health Statistics


Topics
Topics

  • Definition of “drug”

  • Issues in drug utilization analyses

  • Coding issues

  • Examples of trend analyses


Definition of drug
Definition of “Drug”

NHANES

  • A drug is defined as a unique combination of generic ingredients.

    N/HAMCS

  • Recorded on visit record and abstracted verbatim


Nhanes drug data
NHANES Drug Data

  • All drugs used in the past month at time of survey interview

  • Only prescription drugs are included, with a few exceptions

  • Example:

    --penicillin

    --penicillin, clavulanate potassium

  • More closely approximates “prevalence” of use


N hamcs drug data
N/HAMCS Drug Data

  • Up to six drugs recorded (until 2003)—possible biases for drugs that are not salient to the physician or patient (e.g., PRN drugs)

  • Both prescription and non-prescription drugs are included

  • No information is available on compliance or use

  • Approximates prescribing patterns of drugs associated with medical care visits


Issues in drug utilization analyses nhanes
Issues in Drug Utilization AnalysesNHANES

Strengths:

  • Nationally representative and population-based

  • Examination, laboratory and questionnaire data on conditions, biochemical markers, nutrition, health status, and other items

  • Respondent-reported sociodemographic data (e.g., race and ethnicity are collected from respondent)


Issues in drug utilization analyses nhanes1
Issues in Drug Utilization AnalysesNHANES

Possible Limitations:

  • Small sample size for less frequently prescribed drugs and small population subgroups

  • No trade names that help to determine therapeutic use on public use file

  • Respondents may not report use of some drugs


Issues in drug utilization analyses n hamcs
Issues in Drug Utilization AnalysesN/HAMCS

Strengths:

  • Nationally representative

  • Physician/hospital characteristics

  • Conditions (from medical record—but limited number)

  • Selected procedures and tests

  • Relatively large sample size of visits


Issues in drug utilization analyses n hamcs1
Issues in Drug Utilization AnalysesN/HAMCS

Possible Limitations:

  • Limited sociodemographic data

  • Race/ethnicity data are reported by provider, not patient

  • Limited information on episodes or continuity of care

  • No data on compliance or actual utilization

  • Censoring of both drugs and diagnoses

  • Drugs are recorded verbatim from visit records, with possible misspelling


Issues in drug utilization analyses n hamcs2
Issues in Drug Utilization AnalysesN/HAMCS

Factors influencing N/HAMCS counts of drugs:

  • Person must have visited a physician or OPD

  • The more visits made for a specific condition requiring a specific drug, the greater the count of that drug on the N/HAMCS


Coding drug data into therapeutic classes why
Coding Drug DataInto Therapeutic Classes: Why?

Therapeutic classes are useful in determining trends in treatment because:

  • There may be competing drugs that are used for the same condition

  • Guidelines may suggest a class of drugs for treatment of a condition, not a specific drug

  • There are too many individual drugs to analyze each individually!

  • Ideally, one wants to group “like” drugs together


Fda s national drug code ndc therapeutic classes
FDA’s National Drug Code (NDC) Therapeutic Classes

  • Used by both N/HAMCS and NHANES on public use files

  • Code set is nonproprietary and downloadable from the FDA website

  • Identifies each of 20 major drug classes

  • Two-digit categories are general and represent all sub-categories (e.g., 03, Antimicrobial agents)

  • Specific four-digit categories represent the breakouts of the general category (e.g., 0346, Penicillins).


Coding issues with fda s national drug code ndc therapeutic classes
Coding IssuesWith FDA’s National Drug Code (NDC) Therapeutic Classes

Some therapeutic categories are based on indication, while others are based on chemical composition or chemical mechanism

--Examples:

NDC Class 1374/Anticonvlusants

or

NDC Class 1945/Cough and Cold remedies

or

NDC Class 0512/Beta Blocker


FDA’s Therapeutic Drug

Class Codes

  • When using any therapeutic drug class codes, need to review the drugs that are included under that category.

  • Ask yourself- “Is this the list of products I am interested in?”

  • When using NAMCS/NHAMCS or NHANES, look at FDA’s therapeutic drug classes and each drug under those classes.

    • Is the drug class coding sufficient for your research?

    • If not, manually review drugs and recategorize using the generic name codes


Coding issues
Coding Issues

  • Only generic ingredients provided on NHANES public use file, and some N/HAMCS drugs are reported as generic drugs (e.g., “aspirin”)

  • “Main reason for use” is collected and coded into ICD-9-CM classification

  • Some drugs have the same ingredients but different strengths, or different routes of administration that help determine therapeutic use

    Examples: Asthma drugs


Coding issues changes over time
Coding IssuesChanges Over Time

  • N/HAMCS 1980-2001: one NCD therapeutic class on PUF for each drug recorded

  • N/HAMCS 2002-2006: up to three NCD therapeutic classes on PUF for each drug recorded

  • NHANES 1988-94: three NDC therapeutic classes on PUF for each drug reported

  • NHANES 1999-2000: six NDC therapeutic classes on PUF for each drug reported


Coding issues changes over time1
Coding IssuesChanges Over Time

  • Approved indications for drugs change over time (added or subtracted)

  • “Major” uses for drugs with multiple therapeutic uses change over time

  • Drugs may be replaced by other similar drugs

  • Codes and categories are periodically revised

  • Codes do not reflect “off-label” use


Coding issues changes over time2
Coding IssuesChanges Over Time

  • Because therapeutic indications change over time

    • Analysts can merge the most current classifications to drug data from previous years

    • Otherwise drugs may be classified differently in different data years

  • This is less of an issue when analyzing specific drugs


Drugs Prescribed, Administered or Provided During Physician Office or OPD Visits, by NDC Therapeutic Drug Class, 1995-96 and 2001-02

SOURCE: Centers for Disease Control and Prevention, National Center for Health Statistics, National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey.


Coding issues multiple therapeutic indications
Coding Issues Office or OPD Visits, by NDC Therapeutic Drug Class, 1995-96 and 2001-02Multiple Therapeutic Indications

  • Do you allow drugs with multiple approved indications to be double counted?

  • Example:

    • Aspirin has multiple therapeutic uses.

  • More of an issue when comparing or ranking categories than for analyses within a given therapeutic category


Coding issues drugs with overlapping classifications in fda ndc therapeutic classes

Aspirin: Office or OPD Visits, by NDC Therapeutic Drug Class, 1995-96 and 2001-02

1724  Antiarthritics  

1722  Non-Narcotic analgesics  

1728  Antipyretics

Acetaminophen

1722  Non-Narcotic Analgesics  

1728  Antipyretics

Ibuprofen

1724  Antiarthritics

 1722  Non-Narcotic Analgesics

 1727  NSAID

Toradol

1720  General Analgesics

 1722  Non-Narcotic Analgesics

 1727  NSAID

Celebrex

1724  Antiarthritics

1727  NSAID

Meloxicam

1724  Antiarthritics

1727  NSAID

Coding IssuesDrugs with Overlapping Classifications in FDA NDC Therapeutic Classes


Antidepressant use in n hamcs and nhanes
Antidepressant Use in N/HAMCS and NHANES Office or OPD Visits, by NDC Therapeutic Drug Class, 1995-96 and 2001-02

Sources: National Health and Nutrition Examination Surveys, National Ambulatory Medical Care Surveys and National Hospital Ambulatory Medical Care Surveys


Cholesterol Drugs Prescribed, Administered Or Provided During Physician Office And Outpatient Department Visits, By Age Group: United States, 1995-2001

Statin only

80 years and over

Other anti-cholesterol drugs

65-79 years

40-54 years

65-79 years

SOURCE: Centers for Disease Control and Prevention, National Center for Health Statistics, National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey.


Coming soon
Coming Soon….. During Physician Office And Outpatient Department Visits, By Age Group: United States, 1995-2001

Watch for Health, United States, 2004, with Special Feature on Drugs!

  • Overall use

  • Asthma drugs

  • Psychotherapeutic drugs used by children

  • Antidepressant use by adults

  • Anti-cholesterol drugs

  • NSAIDs


Prescription drug use in past month by race and ethnicity 1999 2000
Prescription Drug Use in Past Month, by Race and Ethnicity, 1999-2000

Source: Centers for Disease Prevention and Control, National Center for Health Statistics, National Health and Nutrition Examination Survey


Percent of asthma visits with long term control drugs prescribed ordered or provided 1995 2002
Percent of Asthma Visits with Long-Term Control Drugs Prescribed, Ordered or Provided, 1995-2002

SOURCE: Centers for Disease Control and Prevention, National Center for Health Statistics,

National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey.


ad