RESEARCHERS’ GUIDE TO VA DATA

Examining Veterans’ Pharmacy Use 

with VA and Medicare Pharmacy 

Data

February 3, 2014

Presented by:

Kevin T. Stroupe, PhD

1

VIReC Database and Methods Cyber Seminar Series
RESEARCHERS’ GUIDE TO VA DATA

Audience Poll

Have you ever used VA Pharmacy Data?

– Yes

– No

How would you rate your overall 

knowledge of VA Pharmacy Data?

– 1 (Never Used)

– 2

– 3

– 4

– 5 (Used Frequently, Very familiar)

2
RESEARCHERS’ GUIDE TO VA DATA

Session Objectives

How has outpatient pharmacy data been 

used in VA studies?

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA pharmacy databases

Where to go for more help

3
RESEARCHERS’ GUIDE TO VA DATA

Session Objectives

How has outpatient pharmacy data been 

used in VA studies?

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA pharmacy databases

Where to go for more help

4
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies?

Trends in Medication Use

Tarlov E, Stroupe 

KT, et al. Support 

Care Cancer. 2012; 

20: 1649–57

Pharmacy data 

was used to 

assess trends in 

medication use

5
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies?

Cohort Identification

6

Ng B, et al. Arthritis Care 

& Research. 2012; 64: 

1490–96

Pharmacy data used for 

cohort identification
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies?

Medication Use

Gellad WF, et al. 

Med Care. 2012; 50: 

954–60

Pharmacy data used 

to examine 

antipsychotic 

medication use

7
RESEARCHERS’ GUIDE TO VA DATA

Session Objectives

How has outpatient pharmacy data been 

used in VA studies? 

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA pharmacy databases

Where to go for more help

8
RESEARCHERS’ GUIDE TO VA DATA

Pharmacy Data Sources

Local Databases

– VistA

National Data Sources

– Pharmacy Benefit Management (PBM) 

– Decision Support System (DSS) National 

Data Extract (NDE) Pharmacy Datasets

– Corporate Data Warehouse (CDW)

– Medicare Part D events data from Part D 

Slim File

9
RESEARCHERS’ GUIDE TO VA DATA

Pharmacy Data Sources

Other Key Pharmacy Data Sources

– DSS Product Table

– National Drug File

Note: These are not person-level files

10
RESEARCHERS’ GUIDE TO VA DATA

Audience Poll

Which national sources of VA pharmacy 

data have you used in the past?

– DSS NDE Pharmacy Data

– PBM Pharmacy Data

– CDW Pharmacy Data

– Part D Slim File

– None

11
RESEARCHERS’ GUIDE TO VA DATA

VA Pharmacy Data Sources

VA Pharmacy Benefits Management (PBM) 

Database

– Outpatient Data available from FY1999

– Inpatient Data available from FY2004

– Source of pharmacy data is local VA 

facilities’ VistA systems

– Includes records for inpatient and outpatient 

prescriptions from VA pharmacies or 

Consolidated Mail Outpatient Pharmacy (CMOP)

– Housed by PBM and available through custom 

extracts

12
RESEARCHERS’ GUIDE TO VA DATA

VA Pharmacy Data Sources

VA Decision Support System (DSS) 

National Data Extract (NDE) Pharmacy 

Datasets

– Data available from FY2005

– Includes records for inpatient and outpatient 

prescriptions from VA pharmacies or 

Consolidated Mail Outpatient Pharmacy (CMOP)

– Source of pharmacy data is the local VA facilities’ 

VistA systems

– Housed at Corporate Data Warehouse (CDW) and 

available through custom extracts 

13
RESEARCHERS’ GUIDE TO VA DATA

VA Pharmacy Data Sources

CDW Pharmacy Data

– Data available from FY 2000

– Source of pharmacy data is VistA

– CDW has two pharmacy production domains

• Outpatient Pharmacy

• Bar Code Medication Administration (BCMA)

14
RESEARCHERS’ GUIDE TO VA DATA

VA Pharmacy Data Sources

Select CDW Tables 

– Pharmacy BCMA 

• Dispensed Drug

• Medication Log

• Medication Variance

• Missing Dose Request

– Pharmacy Outpatient

• RxOutPat Prescriptions

• RxOutPat Fill

• RxOutPat Sig

• RxOutPat Medication Instructions

15
RESEARCHERS’ GUIDE TO VA DATA

Comparison of VA Pharmacy Data 

Sources

PBM DSS CDW

Cost Data Drug supply cost Actual cost (ACT_COST)

Dispensing cost 

(DISPCOST)

Supply cost (VS_COST)

Cost available

Access Researcher 

requested extract

Researcher 

requested extract

Researcher 

requested extract

Data 

availability

FY1999 (Outpatient)

FY2004 (Inpatient)

FY2005 (Outpatient & 

Inpatient)

FY2000

Directions 

for use

SIG available (also 

components of SIG 

available: SCHED, 

UNT_DOSE, DSP_UNT)

Not Available SIG available

16
RESEARCHERS’ GUIDE TO VA DATA

Medicare Part D

About a third of VHA/Medicare enrolled 

Veterans are enrolled in Medicare Part D

Different than Medicare Parts A & B

– Claims for drugs are paid for by insurance 

companies, not the Center for Medicare & 

Medicaid Services (CMS)

– Insurance companies submit data to CMS on all 

prescriptions filled

Data for research use

– Prescription Drug Event (PDE)

– Drug, Pharmacy, Prescriber, Plan Characteristics 

– Slim File is subset of PDE data

17
RESEARCHERS’ GUIDE TO VA DATA

Medicare Part D

Medicare Part D Pharmacy Data

– Beginning January 1, 2006 drug coverage became 

available to Medicare enrollees through Medicare Part D 

drug benefit 

– Medicare Part D enrollment status in Medicare 

Enrollment Files

– Important Variables in Medicare Enrollment Files 

include

• Number of months of Part D coverage

• Type of Part D plan (e.g., Managed care plan, prescription 

drug plan [PDP])

– Medicare Data available from VIReC as custom extracts

– Medicare Part D enrollment data are available from CY 

2006 

18
RESEARCHERS’ GUIDE TO VA DATA

Medicare Part D

Medicare Part D Slim File

– 13 variables from Medicare Prescription Drug Event 

(PDE) data are available in Part D Slim File

– Part D Slim File Data are available from VIReC as 

custom extracts

– Data are available from CY 2006

19
RESEARCHERS’ GUIDE TO VA DATA

Medicare Part D

Medicare Part D Slim File variables include:

– Service Date

– Product Service ID – National Drug Code (NDC)

– Quantity Dispensed

– Days Supply

– Patient Payment

– Gross Drug Cost 

– Brand Name

– Generic Name

– Drug Strength

– Dosage Form – Tablet, capsule, etc.

20
RESEARCHERS’ GUIDE TO VA DATA

Key Pharmacy Variables

Variable DSS PBM CDW Part D 

Slim File

Days Supply X X X X

Drug 

Description X X X X

Quantity X X X X

NDC X X X X

Drug class X X X

21
RESEARCHERS’ GUIDE TO VA DATA

Other Pharmacy Data

DSS Product Table

– Key Variables

• IPNum, Feeder Key, Description (short and long), 

Drug Class

• Feeder Key => 1st 5 characters are VA product file 

IEN; last 12 characters are NDC

– Available on DSS Intranet website

National Drug File

– Key Variables

• VA_PRODUCT, FEEDER KEY, NDF_NDC, VA_CLASS

– Available on PBM Intranet website

Note: These are not person-level files

22
RESEARCHERS’ GUIDE TO VA DATA

23

Session Objectives

How has outpatient pharmacy utilization 

been measured in VA studies?

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA Pharmacy databases

Where to go for more help
RESEARCHERS’ GUIDE TO VA DATA

Assessing Outpatient Pharmacy Use:

Finding info in VA Pharmacy Datasets

Where can I find cost variables?

DSS and PBM contain different cost variables

– PBM: cost of the drug product from the supplier

– DSS: 

1) Dispensing Cost (DISPCOST): direct pharmacist 

labor for dispensing the prescription and the 

mailing costs

2) Supply Cost (VS_COST): Drug product cost and 

cost of supplies used in preparing the 

prescription, such as bottles and labels

3) Actual Cost (ACT_COST): Drug product cost, 

cost of supplies such as bottles and labels to 

prepare the prescription, indirect costs, and 

overhead

24
RESEARCHERS’ GUIDE TO VA DATA

Assessing Outpatient Pharmacy Use:

Finding info in VA Pharmacy Datasets

Where can I find cost variables? (Cont.)

Part D Slim File

1) Patient Pay Amount (PTNT_PAY_AMT): 

Amount patient pays for medication

2) Gross Drug Cost (TOT_RX_CST_AMT): 

This variable is derived from the sum of 

Ingredient Cost Paid, Dispensing Fee Paid, 

Total Amount Attributed to Sales Tax, 

Vaccine Administration Fee

25
RESEARCHERS’ GUIDE TO VA DATA

26

Assessing Outpatient Pharmacy Use:

Finding info in VA Pharmacy Datasets

Why is the NDC for the same prescription 

different on the PBM record than on the 

DSS record?

The NDC’s are obtained from different sources

Differences can result if Local Drug File has not been 

updated to reflect supply that was stocked when 

medication was dispensed

Different NDC’s will refer to the same drug, 

dosage, and strength, but may indicate a 

different manufacturer and/or package size
RESEARCHERS’ GUIDE TO VA DATA

27

Session Objectives

How has outpatient pharmacy utilization 

been measured in VA studies?

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA Pharmacy databases

Where to go for more help
RESEARCHERS’ GUIDE TO VA DATA

Assessing Outpatient Pharmacy Use:

Examples of Questions Addressed with Pharmacy Data

Cohort identification

– Can pharmacy data be used to identify specific groups of 

patients?

Medication utilization

– Recent year? Longer historical view? Does policy change 

impact medication use?

Healthcare quality

– Are patients being prescribed medications in accordance with 

quality measures?

Medication adherence

– How much of a prescribed medication are patients using?

Exposure to specific medications or medication 

classes

– Are specific drugs associated with better/worse outcomes?

Combining outpatient and pharmacy data to identify 

events

– Can we identify acute exacerbations of COPD with outpatient 

and prescription data?

Assessing comorbidity or case-mix with medication 

data

28
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies? 

Trends in Medication Use

Tarlov E, Stroupe KT, et al. 

Support Care Cancer. 

2012; 20:1649–57

Objective: To examine 

erythropoiesis-stimulating 

agent (ESA) therapy in 

lung and colon cancer 

patients receiving 

chemotherapy from 2002 

to 2008

29
RESEARCHERS’ GUIDE TO VA DATA

30

Trends in Medication Use:

Tarlov et al. Support Care Cancer. 2012

1/1/07

Study Timeline FDA Issues Black Box Warning, 3/2007

POST Period

PRE Period

12/31/09

1/1/02

How was pharmacy data used?

– Pharmacy data was use to examine

• Whether ESA use differed before (PRE) or after 

(POST) the black box warning

• Trends in ESA use over time 
RESEARCHERS’ GUIDE TO VA DATA

Trends in Medication Use:

Tarlov et al. Support Care Cancer. 2012

Source of pharmacy data

– PBM Database was used to identify ESA use

How were ESAs identified in the PBM 

Database?

– NDCs were used to identify the ESAs in the PBM 

database

31
RESEARCHERS’ GUIDE TO VA DATA

Trends in Medication Use:

Tarlov et al. Support Care Cancer. 2012

For lung cancer patients

Odds of ESA use decreased 65% in the POST period

For colon cancer patients

Odds of ESA use decreased 53% in the POST period

Adapted from Tarlov et al

Support Care Cancer. 2012 32
RESEARCHERS’ GUIDE TO VA DATA

Trends in Medication Use:

Tarlov et al. Support Care Cancer. 2012

ESA use began to decline for both cancer groups before black 

box warning was issued

0 .05 .1 .15 .2 .25 .3 .35 .4 .45

Probability

2002 2003 2004 2005 2006 2007 2008

Colon (N=4,225)

Lung (N=17,014)

Diagnosis Year

March 2007: FDA “black box” warning

Adapted from Tarlov et al 33

Support Care Cancer. 2012
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies? 

Cohort Identification

34

Ng B, et al., Arthritis Care 

Research. 2012; 64:1490–96

Objective: To assess the utility 

of diagnostic algorithms, 

including prescriptions, to 

identify rheumatoid arthritis 

patients within VHA database

 

s
RESEARCHERS’ GUIDE TO VA DATA

Cohort Identification:

Ng et al. Arthritis Care Research. 2012

Study sample consisted of patients having 2 

outpatient visits with rheumatoid arthritis 

(RA) codes at least 2 months apart at Houston 

VAMC between FY99 and FY09

How was pharmacy data used?

– Study tested algorithms to identify RA in through VHA 

databases using

• Presence of at least 2 ICD-9 at least 6 months apart

• Use of disease-modifying antirheumatic drugs (DMARD)

for at least 180 days 

• ICD-9 code for RA at visit to rheumatologist

35
RESEARCHERS’ GUIDE TO VA DATA

Cohort Identification:

Ng et al. Arthritis Care Research. 2012

Study design

– To validate diagnosis of RA, study conducted chart 

review

– Study evaluated the positive predictive value (PPV) of 

the diagnostic algorithms using validation from chart 

review

Source of Pharmacy Data

– PBM Database

36
RESEARCHERS’ GUIDE TO VA DATA

Cohort Identification:

Ng et al. Arthritis Care Research. 2012

Adapted from Ng et al. Arthritis 37

Care Research. 2012
RESEARCHERS’ GUIDE TO VA DATA

How has pharmacy data been used in VA studies? 

Medication Use

Gellad WF, et al., Med 

Care. 2012;50: 954–60.

Objective: To assess the 

prevalence and risk factors 

for antipsychotic use in 

older residents of VA 

Community Living Centers 

38
RESEARCHERS’ GUIDE TO VA DATA

Medication Use:

Gellad et al. Med Care. 2012

Antipsychotic medications are commonly 

prescribed to nursing home residents 

despite well-established adverse events

Cohort consisted of all residents of VA 

Community Living Center between 

1/1/2004 and 6/30/2005 with at least 

VA Rx dispensing

Logistic regression used to indentify 

factors associated with antipsychotic use

39
RESEARCHERS’ GUIDE TO VA DATA

Medication Use:

Gellad et al. Med Care. 2012

How was pharmacy data used?

– Pharmacy data was linked with Minimum Data Sets 

(MDS) and MedSAS data

– For each dispensed drug, study collected

• Start and stop date

• Medication name

• Medication strength

• Directions for use (i.e., SIG)

• Amount dispensed

– To create a polypharmacy covariate for analysis, the 

study identified the number of unique drugs per resident

Source of Pharmacy Data

– PBM Database 40
RESEARCHERS’ GUIDE TO VA DATA

Medication Use:

Gellad et al. Med Care. 2012

Resident classified based on whether there were 

indications for antipsychotic medications

– Appropriate use included patients with psychiatric 

diagnosis in which psychotic symptoms are prominent 

feature or a diagnosis of dementia and psychotic 

symptoms

– Potentially inappropriate use were remaining patients 

without psychiatric diagnosis or psychotic symptoms

41
RESEARCHERS’ GUIDE TO VA DATA

Medication Use:

Gellad et al. Med Care. 2012

Antipsychotic used during Community Living 

Center Stay by:

– 948 (25.7%) of 3692 Veterans

Of those with Antipsychotic medications:

– 59.3% had documented indication for appropriate use

– 40.7% had no evidence of appropriate indication for use

Adapted from Gellad et al. 42

Med Care. 2012
RESEARCHERS’ GUIDE TO VA DATA

43

Session Objectives

How has outpatient pharmacy utilization 

been measured in VA studies?

Overview of VA and Medicare pharmacy 

databases

Finding information in the VA and 

Medicare pharmacy databases

Examples of VA studies that have used 

the VA Pharmacy databases

Where to go for more help
RESEARCHERS’ GUIDE TO VA DATA

44

VIReC Help

VIReC Webpage 

http://www.virec.research.va.gov/Pharmacy/

Overview.htm

– Information on VA pharmacy sources

– Resource users guide for pharmacy data

• http://www.virec.research.va.gov/RUGs/RUG-PBM2nd-Ed-CY08-ER.pdf
RESEARCHERS’ GUIDE TO VA DATA

45

VIReC Help (cont’d)

HSRData Listserv

– Join at the VIReC Web site

– Discussion among >400 data stewards, 

managers, and users

– Past messages in archive (on intranet)

VIReC Help Desk

– VIReC staff will answer your question and/or 

direct you to available resources on topics

– VIReC@va.gov 

– (708) 202-2413
RESEARCHERS’ GUIDE TO VA DATA

46

Questions?
RESEARCHERS’ GUIDE TO VA DATA

Selected Recent References on 

VA Outpatient Pharmacy Use

Berlowitz, D. R. & Pugh, M. J. (2007). Pharmacoepidemiology in community-dwelling 

elderly taking antiepileptic drugs. Int Rev Neurobiol., 81:153-63., 153-163.

Damush, T. M., Jia, H., Ried, L. D., Qin, H., Cameon, R., Plue, L. et al. (2008). Case- finding algorithm for post-stroke depression in the veterans health administration. Int 

J Geriatr Psychiatry., 23, 517-522.

Davis, R. G., Hepfinger, C. A., Sauer, K. A., & Wilhardt, M. S. (2007). Retrospective 

evaluation of medication appropriateness and clinical pharmacist drug therapy 

recommendations for home-based primary care veterans. Am J Geriatr 

Pharmacother., 5, 40-47.

Frayne, S. M., Yu, W., Yano, E. M., Ananth, L., Iqbal, S., Thrailkill, A. et al. (2007). 

Gender and use of care: planning for tomorrow's Veterans Health Administration. J 

Womens Health (Larchmt.)., 16, 1188-1199.

Gellad WF, Aspinall SL, Handler SM, Stone RA, Castle N, Semla TP, Good CB, Fine MJ, 

Dysken M, Hanlon JT. Use of Antipsychotics Among Older Residents in VA Nursing 

Homes. Med Care. 2012;50: 954–960. 

Huetsch JC, Uman JE, Udris EM, Au DH. Predictors of Adherence to Inhaled 

Medications Among Veterans with COPD. J Gen Intern Med. 2010; 27(11):1506–12.

Iqbal, S. U., Cunningham, F., Lee, A., Wang, S., Hamed, A., Miller, D. R. et al. 

(2007). Divalproex sodium vs. valproic acid: drug utilization patterns, persistence 

rates and predictors of hospitalization among VA patients diagnosed with bipolar 

disorder. J Clin Pharm Ther., 32, 625-632.

47
RESEARCHERS’ GUIDE TO VA DATA

Selected Recent References on 

VA Outpatient Pharmacy Use (cont)

Jia, H., Damush, T. M., Qin, H., Ried, L. D., Wang, X., Young, L. J. et al. (2006). 

The impact of poststroke depression on healthcare use by veterans with acute 

stroke. Stroke., 37, 2796-2801.

Lee, T. A., Pickard, A. S., Au, D. H., Bartle, B., & Weiss, K. B. (2008). Risk for 

death associated with medications for recently diagnosed chronic obstructive 

pulmonary disease. Ann Intern Med., 149, 380-390.

Mahmood, M., Malone, D. C., Skrepnek, G. H., Abarca, J., Armstrong, E. P., 

Murphy, J. E. et al. (2007). Potential drug-drug interactions within Veterans 

Affairs medical centers. Am J Health Syst Pharm., 64, 1500-1505.

Mortensen, E. M., Restrepo, M. I., Copeland, L. A., Pugh, J. A., Anzueto, A., 

Cornell, J. E. et al. (2007). Impact of previous statin and angiotensin II receptor 

blocker use on mortality in patients hospitalized with sepsis. Pharmacotherapy., 

27, 1619-1626.

Ng B, Aslam F, Petersen NJ, Yu HJ, Suarez-Almazor ME. Identification of 

Rheumatoid Arthritis Patients Using an Administrative Database: A Veterans 

Affairs Study. Arthritis Care & Research. 2012; 64:1490–1496.

Poon, I. O., Lal, L., Brown, E. N., & Braun, U. K. (2007). The impact of 

pharmacist-managed oral anticoagulation therapy in older veterans. J Clin 

Pharm Ther., 32, 21-29.

48
RESEARCHERS’ GUIDE TO VA DATA

Selected Recent References on 

VA Outpatient Pharmacy Use (cont)

Pugh MJV, Copeland LA, Zeber JE, et al. Antiepileptic drug monotherapy 

exposure and suicide-related behavior in older Veterans. J Am Geriatr Soc. 2012 

Nov;60(11):2042-7.

Sernyak, M. J. & Rosenheck, R. A. (2008). Antipsychotic use in the treatment of 

outpatients with schizophrenia in the VA from fiscal years 1999 to 2006. 

Psychiatr Serv., 59, 567-569.

Tarlov E, Stroupe KT, et al. Trends in anemia management in lung and colon 

cancer patients in the US Department of Veterans Affairs, 2002-2008. Support 

Care Cancer. 2012; 20:1649–1657 

VIReC Technical Report: Comparison of VA Outpatient Prescriptions in the DSS 

Datasets and the PBM Database

http://vaww.virec.research.va.gov/References/TechnicalReports/VIReCTechnical

Report1.pdf. 

Walbrown, M. A., Aspinall, S. L., Bayliss, N. K., Stone, R. A., Cunningham, F., 

Squier, C. L. et al. (2008). Evaluation of Clostridium difficile-associated diarrhea 

with a drug formulary change in preferred fluoroquinolones. J Manag Care 

Pharm., 14, 34-40.

49
RESEARCHERS’ GUIDE TO VA DATA

50

Upcoming Seminar

Using CAPRI and VistAWeb - March 3, 2014

Linda Williams, MD