Analyzing data on medications Analyzing data on medications collected in the National Health Care collected in the National Health Care

SurveySurvey

Centers for Disease Control and PreventionNational Center for Health Statistics

Catharine W. Burt , Ed.D.

Chief, Ambulatory Care Statistics Branch

June 6, 2004 AcademyHealth Conference

TopicsTopics

Overview of the NHCSOverview of the NHCS Background of the ambulatory care Background of the ambulatory care

surveyssurveys Using public use files for drug analysisUsing public use files for drug analysis Examples of drug analysesExamples of drug analyses

Ambulatory care

Long-term care

National Health Care SurveyNational Health Care SurveyBasic Components

Hospital &surgical care

Health ProviderInventory

National Health Care SurveyNational Health Care Survey(Year began collecting drug data)(Year began collecting drug data)

National Ambulatory Medical Care Survey National Ambulatory Medical Care Survey (1980)(1980)

National Hospital Ambulatory Medical Care National Hospital Ambulatory Medical Care Survey Survey (1992)(1992)

National Hospital Discharge Survey National Hospital Discharge Survey (in research)(in research) National Survey of Ambulatory Surgery National Survey of Ambulatory Surgery (1994-6)(1994-6)

National Nursing Home Survey National Nursing Home Survey (2004)(2004) National Home and Hospice Care SurveyNational Home and Hospice Care Survey

Increasing drug mentions at ambulatory care visitsIncreasing drug mentions at ambulatory care visits

NHCS Common MethodologyNHCS Common Methodology

National probability sample surveys Complex sample designs Common definitions, data items, sampling

frames Medical diagnoses coded to ICD-9-CM Data collected by Census Bureau High response rates Data processed by private contractor

Antibiotic prescribing rates at Antibiotic prescribing rates at

physician office visits for childrenphysician office visits for children

0

200

400

600

800

1000

89/90 91/92 93/94 95/96 97/98 99/00

Year

Rate per 1000 population

Rate per 1000 visits

NAMCS and NHAMCS NAMCS and NHAMCS background background

NAMCS NAMCS Fielded 1973-1981, 1985, 1989-presentFielded 1973-1981, 1985, 1989-present 3-stage sample3-stage sample

• PSUs – PSUs – physicians – physicians – visits during 1 weekvisits during 1 week

NHAMCS NHAMCS Fielded annually since 1992Fielded annually since 1992 4-stage sample4-stage sample

• PSUs – PSUs – hospitals – hospitals – ED/OPD clinics – ED/OPD clinics –

visits during 4 weeksvisits during 4 weeks

SEs

rates

percents

drugsproviders

visits

sample

records

Scope of the NAMCSScope of the NAMCS

Physicians must be: Physicians must be: Primarily engaged in office-based, patient Primarily engaged in office-based, patient

carecare Nonfederally employedNonfederally employed Not in anesthesiology, radiology, or Not in anesthesiology, radiology, or

pathology pathology

In-Scope Visits for NAMCSIn-Scope Visits for NAMCS

Basic unit of sampling is the physician-Basic unit of sampling is the physician-patient visit patient visit

Visit must occur in a physician’s officeVisit must occur in a physician’s office Visits must be for medical purposesVisits must be for medical purposes Out-of-scope contacts include:Out-of-scope contacts include:

Visits for administrative purposesVisits for administrative purposes House calls, phone calls, emails, visits in House calls, phone calls, emails, visits in

hospital setting unless physician has private hospital setting unless physician has private office thereoffice there

In-Scope NAMCS Locations In-Scope NAMCS Locations Freestanding private solo or group Freestanding private solo or group

practicepractice Freestanding clinic/urgicenterFreestanding clinic/urgicenter Neighborhood medical and mental health Neighborhood medical and mental health

centerscenters Privately operated clinicsPrivately operated clinics Non-Federal government clinicNon-Federal government clinic Health maintenance organizationHealth maintenance organization Federally qualified health centerFederally qualified health center Faculty practice planFaculty practice plan

Out-of-Scope NAMCS Out-of-Scope NAMCS LocationsLocations

Hospital ED’s and OPD’sHospital ED’s and OPD’s Ambulatory surgicenterAmbulatory surgicenter Institutional setting (schools, prisons)Institutional setting (schools, prisons) Industrial outpatient facilityIndustrial outpatient facility Federally operated clinicFederally operated clinic Laser vision surgeryLaser vision surgery

Scope of the NHAMCSScope of the NHAMCS

Basic unit of sampling is patient visitBasic unit of sampling is patient visit Emergency and outpatient departments of Emergency and outpatient departments of

non-federal, general and short-stay non-federal, general and short-stay hospitalshospitals

Not Federal, military, or Veterans Not Federal, military, or Veterans Administration facilitiesAdministration facilities

Located in 50 states and D.C.Located in 50 states and D.C.

Items CollectedItems Collected Patient characteristics Patient characteristics

Age, sex, race, ethnicityAge, sex, race, ethnicity Visit characteristicsVisit characteristics

Source of payment, continuity of care, reason for visit, Source of payment, continuity of care, reason for visit, diagnosis, treatment, medications ordered or provideddiagnosis, treatment, medications ordered or provided

Provider characteristicsProvider characteristics Physician specialty, hospital ownershipPhysician specialty, hospital ownership

Drug characteristicsDrug characteristics Therapeutic class, composition, control status, Therapeutic class, composition, control status,

ingredients, Rx or OTCingredients, Rx or OTC

Using NAMCS/NHAMCS Using NAMCS/NHAMCS public use files for public use files for

analyzing drug dataanalyzing drug data

Ambulatory Care Data StructureAmbulatory Care Data Structure

Providerprovider infopractice info

geographic info

Visit patient & visit info

treatment & outcome infomedications

Visit Visit

Medcode 1…Medcode 6

Class 1 Ingredient 1 ..ingredient 5

…Class 3

File StructureFile Structure

Flat ASCII files for each setting and yearFlat ASCII files for each setting and year Use file layout to read the dataUse file layout to read the data Input and format code available forInput and format code available for

SASSAS STATASTATA SPSSSPSS

Can use SETS Can use SETS (but no sampling variance estimates)(but no sampling variance estimates)

Visit File LayoutVisit File Layout

Patient In fosex, age,

race, ethnicity

Visit In fodate, reason for v is it,

paym ent source, d iagnosis,patient w eight

Treatm ent In fodiagnostic services,

counseling/education,therapeutic services

M edication Infodrug nam e,

generic nam e, ingredients,therapeutic c lass

O utcom e M easuresno FU p lanned,

return, refer,adm it to hospita l

Provider In fospecia lty, reg ion,

urban, so lo practice,ow nership

Setting & Year

Sample WeightSample Weight

Each NAMCS, OPD and ED record Each NAMCS, OPD and ED record contains a single weight, which we call contains a single weight, which we call Patient Visit WeightPatient Visit Weight

This weight is used for both visits and This weight is used for both visits and drug mentionsdrug mentions

Weight must be applied or estimates of Weight must be applied or estimates of totals, percents and effects will be totals, percents and effects will be incorrect.incorrect.

Drug codingDrug coding

Drug nameDrug name Generic nameGeneric name Therapeutic Therapeutic classclass

ProzacProzac

MED#=25674MED#=25674

FluoxetineFluoxetine

GEN#=80006GEN#=80006

AntidepressantAntidepressant

DRUGCL=0630DRUGCL=0630

FluoxetineFluoxetine

MED#=91079MED#=91079

FluoxetineFluoxetine

Gen#=80006Gen#=80006

AntidepressantAntidepressant

DRUGCL=0630DRUGCL=0630

Fluoxetine HCLFluoxetine HCL

MED#=91079MED#=91079

FluoxetineFluoxetine

GEN#=80006GEN#=80006

AntidepressantAntidepressant

DRUGCL=0630DRUGCL=0630

Leading Rx at office visitsLeading Rx at office visits % of all Rx mentions% of all Rx mentions

Lipitor Lipitor 1.6% 1.6% AlbuterolAlbuterol 1.41.4 Amoxicillin Amoxicillin 1.31.3 Synthroid Synthroid 1.31.3 Lasix Lasix 1.2 1.2 Celebrex Celebrex 1.21.2 Vioxx Vioxx 1.11.1

Source: 2002 NAMCSSource: 2002 NAMCS

Top OTC mentions at office visitsTop OTC mentions at office visits % of all OTC mentions% of all OTC mentions

Aspirin Aspirin 16.7% 16.7%Tylenol Tylenol 11.6 11.6Advil 4.1Advil 4.1Prenatal vitamins 3.4Prenatal vitamins 3.4Benadryl Benadryl 3.2 3.2

Source: 2002 NAMCSSource: 2002 NAMCS

http://www.cdc.gov/nchs/about/major/ahcd/ahcd1.htmhttp://www.cdc.gov/nchs/about/major/ahcd/ahcd1.htm

Drug Characteristics Database Search

on Generic: Fluoxetine

1999

Drug Code Drug Name Generic Name Mentions

25674 PROZAC FLUOXETINE

HYDROCHLORIDE 9,257,694

91079 FLUOXETINE FLUOXETINE

HYDROCHLORIDE 49,293

Drug Characteristics Database

Drug Code\Name: 25674 - PROZAC

Generic Code\Name: 80006 – FLUOXETINE

HYDROCHLORIDE

Date Added: No Date

Prescription Status: 1 - Prescription Drug

Composition Status: 1 - Single Entity Drug

DEA Status: 6 - No Control

Therapeutic Class: 0630 Antidepressants

1999 Mentions: 9,257,694

1999 Mention Rate: 98.0

Drug Characteristics Database

Drug Code\Name: 91079 - FLUOXETINE

Generic Code\Name: 80006 – FLUOXETINE

HYDROCHLORIDE

Date Added: No Date

Prescription Status: 1 - Prescription Drug

Composition Status: 1 - Single Entity Drug

DEA Status: 6 - No Control

Therapeutic Class: 0630 Antidepressants

1999 Mentions: 49,293

1999 Mention Rate: 1.0

Drug mention rates at physician office Drug mention rates at physician office visits by patient’s age: 1985-2002visits by patient’s age: 1985-2002

1985

1989

-90

1995

-96

1997

-98

1999

-200

0

2001

-20

50

100

150

200

250

Dru

g m

en

ti on

s p

er

10

0 v

isits

<45 45-64 65+

Drug mention rates for Drug mention rates for NSAIDs, antidepressants,NSAIDs, antidepressants, and antihistamines and antihistamines at physician office visits, at physician office visits,

1995-2002 1995-2002

3

4

5

6

7

8

9

1995 1996 1997 1998 1999 2000 2001 2002

Num

ber

of d

rug

men

tions

per

100

vis

its

NSAIDs are nonsteroidal anti-inflammatory drugs.Trends shown are significant (p<0.05).

NSAIDs

Antidepressants

Antihistamines

Estrogen/progestinEstrogen/progestin mention rates for women at mention rates for women at physician office visits by patient age, 1995-2002physician office visits by patient age, 1995-2002

20

25

30

35

40

45

50

55

60

1995 1996 1997 1998 1999 2000 2001 2002

65 years and over

45-64 years

Num

ber

of d

rug

men

tions

per

100

fem

ales

.

Rate of office visits for erectile dysfunction Rate of office visits for erectile dysfunction for men 25+: United States, 1985-2002for men 25+: United States, 1985-2002

"

"

"

"

"

1985

1989

-90

1995

-96

1999

-200

0

2001

-200

20

5

10

15

20

25

Num

ber

of v

isits

pe r

1, 0

0 0 m

a le s Viagra introduced

Figures are based on 2-year averages except 1985. SOURCE: NAMCS

Example of NAMCS analysis for ViagraExample of NAMCS analysis for Viagra Prescribed at .4% of office visits by males; 15% of Prescribed at .4% of office visits by males; 15% of

erectile dysfunction (ED) visitserectile dysfunction (ED) visits 12% scripts written for men aged 25-44 and 9% for 75+12% scripts written for men aged 25-44 and 9% for 75+ Rate of scripts increases for patients who have seen Rate of scripts increases for patients who have seen

their physician between 1 and 5 times in past year. their physician between 1 and 5 times in past year. Rarely prescribed at an initial visit.Rarely prescribed at an initial visit.

Only 19% of scripts written are at ED visitsOnly 19% of scripts written are at ED visits Leading diagnoses when ED not listed– Leading diagnoses when ED not listed–

Essential hypertension 19%Essential hypertension 19% Hyperplasia of the prostate 11%Hyperplasia of the prostate 11% Diabetes 8%Diabetes 8%

Analyzing trendsAnalyzing trends Be careful about trending diagnosis prior to 1980 Be careful about trending diagnosis prior to 1980

because of ICDAbecause of ICDA (based on ICD-8)(based on ICD-8) Even after 1980- be careful about changes in ICD-Even after 1980- be careful about changes in ICD-

9-CM9-CM Number of medications varies over yearsNumber of medications varies over years

1980-81 – 8 medications1980-81 – 8 medications1985, 1989-94 – 5 medications1985, 1989-94 – 5 medications1995-2002 – 6 medications1995-2002 – 6 medications2003-2006 – 8 medications2003-2006 – 8 medications

Number of therapeutic class codes varyNumber of therapeutic class codes vary1980-2001 – 1 class1980-2001 – 1 class2002-2006 – up to 3 classes2002-2006 – up to 3 classes

Information available on the Information available on the InternetInternet

NCHS website is www.cdc.gov/nchsNCHS website is www.cdc.gov/nchs National Health Care Survey website National Health Care Survey website

Ambulatory Health Care Data (AHCD)Ambulatory Health Care Data (AHCD) National Hospital Discharge and National Hospital Discharge and

Ambulatory Surgery Data (NHDAS-data)Ambulatory Surgery Data (NHDAS-data) National Nursing Home Survey (NNHS)National Nursing Home Survey (NNHS) National Home and Hospice Care Survey National Home and Hospice Care Survey

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