1. Available Types of National Drug Use Data
DSARM Advisory Committee Meeting
Silver Spring, Maryland
May 18, 2005
Judy Staffa, PhD, RPh, Epidemiology Team Leader
Division of Surveillance, Research & Communication Support
Office of Drug Safety
Center for Drug Evaluation and Research

2. Overview Applications of drug use data Typical questions Challenges
Available types of data
by question and setting of care
Summary
Future challenges

3. Applications of drug use data in drug safety
Denominators for putting AERS reports into context (e.g., reporting rates)
Description of prescribing patterns
physicians’ specialty
patient demographics
associated diagnoses/procedures
Insight into duration of use and concomitant use of multiple drugs
Surveillance of risk management practices to restrict drug use
Impact of potential medication errors

4. How many patients in the U.S. take drug A?
“$64,000 question”
How many patients in the U.S. take drug A?

5. Other common questions
What are the demographics of patients on drug A?
How long do patients stay on drug A?
How often do patients take drugs A and B together?
For what indication is drug A prescribed?
By which types of physicians?
What drugs are being prescribed for condition X?

6. Challenges Fragmentation of U.S. health care system “Pockets” of use
Settings of care/payers/buyers
Projections to national estimates for “pocket”
Sum across “pockets”

7. Settings Outpatient (Rx) Pharmacies/Mail order Physician Offices
Clinics
Inpatient
Over-the-counter (OTC)

8. Additional challenges
Secondary data sources
Administrative/billing data
Marketing data
Newer data sources
Linkage across “data streams”

9. How many patients take drug A
How many patients take drug A? What are the demographics of these patients?

10. How many patients/demographics? Outpatient (Pharmacies)
Traditional
National estimates of dispensed prescriptions, projected from
retail pharmacies
mail order
long-term care
Patient age/gender- missing or incomplete
More recent
National estimate of dispensed prescriptions and patients, projected from
multiple data streams (pharmacies, pharmacy benefit managers, insurers)
Patient age & gender
Limitations:
-Doesn’t cover all outpatient settings
-”Dispensed” is not “Taken”

11. How many patients/demographics? Outpatient (Other)
Physician offices
Convenience sample of office visits from physicians
National Ambulatory Medical Care Survey (NAMCS)
Clinics
Little available
Some J-codes in claims
Rely on sales data into clinics
Limitations:
-Sample sizes are often small - unstable projections
-Generalizability questionable
-NAMCS data not timely enough
Limitations:
-Little patient-level information
-Generalizability questionable

12. How many patients/demographics? Inpatient
Traditional
None
More recent
National estimates of discharges in which drug was billed
Discharge-level age & gender, diagnosis and procedure data
Limitations:
-No link to drug indication
-Double-counting of patients
-“Billed” is not “Administered”
-Some areas missing - surgery, radiology
-Unclear universe - e.g., pediatrics

13. How many patients/demographics? Over-the-counter drugs
Traditional
Use sales data as proxy
More recent
Household survey data projected nationally
Limitations:
-Not patient-level
Limitations:
-Unknown

14. How long do patients stay on drug A
How long do patients stay on drug A? How often do patients take drugs A and B together?

15. Duration/concomitancy? Outpatient
Traditional
Longitudinal patient-level insurance claims data
More recent
Longitudinal data linked across data streams, including pharmacy-based
Includes cash payors
Limitations:
-National estimates not possible
-Generalizability questionable
-Not all drugs covered
-”Dispensed” is not “taken”
Limitations:
-Unknown

16. Duration/concomitancy? Inpatient
Traditional
None
More recent
Day of stay billing detail for drugs and procedures
Limitations:
- National estimates not possible
-Generalizability questionable
-Indication unknown
-”Billed” is not “administered”

17. For what indication is drug A prescribed. By which types of physicians
For what indication is drug A prescribed? By which types of physicians? What drugs are being prescribed for condition X?

18. Indication/specialty? Outpatient
Traditional
National estimates of prescribing practices from marketing data
NAMCS
More recent
Electronic medical records
E-prescribing
Limitations:
- Sample size small
-Generalizability questionable
- NAMCS data not timely
Limitations:
-Generalizability questionable
- Research-ready?

19. Indication/specialty? Inpatient
Traditional
None
More recent
Hospital billing data
attending/consulting physician specialty
all discharge diagnoses
Limitations:
-No linkages
*prescriber drug
*drug indication

20. Summary
Our knowledge of drug use in the U.S. is largely setting-specific
Drug use data varies in detail across settings
Outpatient pharmacy - patient/Rx-level Most detail
Outpatient physician office - visit-level
Inpatient - discharge-level
OTC - pilot work on patient-level data
Outpatient clinics - sales only Least detail
Intermediate detail

21. Future Challenges Increased coverage of other care settings
Operating room/radiology
Hospital outpatient clinics (e.g., chemotherapy)
Staff model HMOs
Home health care/long term care
Over-the-counter drugs (patient-level)
Increased coverage of special populations
Elderly (Medicare Part D)
Pediatrics
Pregnant women
HIV-infected (specialty pharmacies)
Further linkage across care settings
Outpatient - inpatient

22. Acknowledgements Drug Use Specialists Epidemiologists
Laura Governale
Michael Evans
David Moeny
Kendra Worthy
Epidemiologists
Aaron Mendelsohn
Sigal Kaplan
Andrea Feight
Tarek Hammad
Contracts Specialists
Katrina Garry
Martha O’Connor
Kathy Rios