Download Presentation

Trends of Oseltamivir Usage in the
United States during the 2009
Influenza A (H1N1) Pandemic
CDR John K. Iskander
LCDR Craig Hales
Charbel el-Bcheraoui
Robert T. Chen
Centers for Disease Control and Prevention
Detection of Novel H1N1 Virus
• March 2009
• 2 cases of febrile respiratory illness
in children (un-related, no pig
contact)
• Residents of adjacent counties in
southern California, ill in late March
• Novel swine influenza A (H1N1) virus
detected at CDC on April 15th,17th
• Both viruses genetically identical
• Contain a unique combination of
gene segments previously not
recognized among swine or human
influenza viruses in the United
States
Retrospective evidence of
respiratory illness outbreaks
in Mexico (February/March)
April 26, 2009
US declares National
Public Health Emergency
June 11, 2009
WHO declares Global
pandemic of novel
influenza A (H1N1) virus
Pandemic H1N1: Disease burden estimates
• In United States, as of 3/13/2010:
– 59.98 million cases
– 270, 435 hospitalizations
– 12, 271 deaths
• Mean age of deaths 37 years
– Source: CDC website
Influenza Antivirals: Background
• Treatment of suspected or confirmed influenza with antiviral medications
is one important strategy to reduce morbidity and mortality caused by the
2009 pandemic influenza A (H1N1) virus (pH1N1)
• The pandemic strain has been susceptible to neuraminidase inhibitors
(NAI) such as oseltamivir (> 99% of isolates)
•
NAI (oseltamivir, zanamivir) antiviral treatment is recommended* as soon as
possible for:
•
All hospitalized patients with suspected, probable, or confirmed 2009 influenza A (H1N1) virus
infection
•
Outpatients with high-risk conditions (including children < 2 years old, pregnant women and
women up to 2 weeks post-pregnancy, persons ages 65 and older, persons with chronic
conditions - chronic lung disease, diabetes, etc.) with suspected, probable, or confirmed 2009
influenza A (H1N1) virus infection
* Current CDC Antiviral Treatment Recommendations
for pH1N1 influenza
http://www.cdc.gov/H1N1flu/recommendations.htm
Objectives
• To monitor the usage of influenza antivirals by
pH1N1 age-specific risk groups, and to assess
related geographic and time trends in the
United States
• To evaluate effectiveness of CDC guidance on
use of antiviral medicines
Monitoring of Influenza Antiviral
Medication Usage
• Through BioSense*, CDC receives anti-infective
prescription data from 27,000 pharmacies,
representing approximately half of U.S. antiinfective prescription data
– Data include patient demographics (age and sex) and
pharmacy zip code
*For more information see www.cdc.gov/biosense
System Description
• BioSense receives prescription data from an electronic
prescriptions claims provider in all 50 states and Washington,
D.C. as well as U.S. territories. Data are updated every 4 hours
• The data collected concern all prescriptions for anti-infective
medicines and include the specific type (brand) and
formulation dispensed
• These data cover about 50% of all anti-infective medicines
prescribed in the states and represent prescriptions requested
at retail pharmacies and approved to be covered by insurance
companies
– Coverage range for prescription transactions for the 9 census divisions:
mean 49.7%, range 42.9-60.7%
Pharmacies — 27,000 Active
Methods
• Rates of antiviral medication prescribing are
calculated using population data from the U.S.
Census, and are compared with national and regional
measures of influenza disease activity
– % of visits for influenza-like illness (ILI) assessed through
U.S. Outpatient Influenza-like Illness Surveillance Network
(ILINet)
• We analyzed oseltamivir (Tamiflu®) prescribing data
by age groups and federal regions from April through
December 2009
Results
Nationwide rates of Rx of Oseltamivir by age groups, USA, 2007-2009
Nationwide rates of Oseltamivir prescribing by age groups
USA, April-December 2009
DHHS Regions I-X
Regional rates of Rx of Oseltamivir by age groups, Federal Region 4,
April-December 2009
Regional rates of Rx of Oseltamivir by age groups, Federal Region 9,
April-December 2009
Summary of Results of Monitoring
• Nationally, highest rates of prescribing were seen shortly after
detection of the pandemic in spring of 2009, as well as in
September-October of 2009
– Two distinct peaks seen in autumn of 2009
• Children (infants, pre-school age, and school age) were
prescribed the medication at the highest rates
• Medication prescribing for all ages has sharply decreased
since November 2009
Results Details
• School-age children (5-18 years) consistently had the highest
prescribing rates, with a peak of > 500 prescriptions/100,000
population during September 2009
• Pre-school age children (2-4) had similar prescribing rates, reaching
450/100,000 in both September and October
• Patterns of prescribing for infants generally paralleled those seen
for older children but with lower peak rates (350/100,000)
• After the initial May peak, prescribing rates for working age adults
(18-64) and the elderly (65 and over) were < 200 courses/100,000
• Regional prescribing patterns clustered geographically, with
prescribing rates in contiguous regions increasing and decreasing
synchronously
Interpretation of findings
• Prescribing rates have been highest overall among pediatric
age groups, who are at high risk of H1N1 illness
• Lower rates of prescribing for those 65 and over are
consistent with low rates of H1N1 disease in this age group
• Rates of prescribing were closely related to levels of influenza
disease activity, both nationally and regionally
• Despite widespread prescribing of oseltamivir, so far no
detection of significant levels of viral resistance or new safety
concerns
Strengths and Limitations
• Strengths
–
–
–
–
Data updated frequently
Significant population coverage
Ability to generate age adjusted prescribing rates
Exploring ability to provide data linked to claims
• Limitations
– Ecologic analysis; no linkage to patient level diagnostic information
– No data from hospital pharmacies
– No coverage for self-pay or those with no prescription insurance
coverage
Conclusions
• Prescribing rates were highest overall among
pediatric age groups, who are at high risk of
H1N1 illness
• Rates of prescribing were closely related to
levels of influenza disease activity, both
nationally and regionally
Future (and Present) Uses of Pharmacy
and other Drug Utilization Data
• Monitoring of both infectious and chronic
diseases
• Use as denominator data for pharmaceutical
safety/adverse event monitoring
• Use by Strategic National Stockpile (SNS) to
monitor formulation shortages and adjust
stockpile distribution
Antiviral Adverse Event Monitoring – Comparison by Season*
December 31, 2009
Influenza Antiviral-Related Emergency Department Visits, 2006-2007 Season to Present
Source: DAWNLive!
180
160
140
No. of Reports
120
100
80
60
40
20
2006-2007 Season
2007-2008 Season
*Note: AE data lagtime is 2-3 weeks.
Rimantadine
2009 H1N1
Oseltamivir
Zanamivir
Dec-09
Nov-09
Oct-09
Sep-09
Aug-09
Jul-09
Jun-09
May-09
Apr-09
Mar-09
Feb-09
2008-2009 Season
Month-Year
Amantadine
Jan-09
Dec-08
Oct-08
Nov-08
Sep-08
Jul-08
Aug-08
Jun-08
May-08
Apr-08
Mar-08
Feb-08
Jan-08
Dec-07
Nov-07
Oct-07
Aug-07
Sep-07
Jul-07
Jun-07
Apr-07
May-07
Mar-07
Jan-07
Feb-07
Dec-06
Oct-06
Nov-06
0
Antiviral AE Monitoring and Antiviral Dispensing, December 31, 2009
Influenza Antiviral-Related Emergency Department Visits (DAWN Live! ) and Influenza Antiviral
Prescriptions (CDC BioSense), October 2008 - Present
180
1,400.0
160
1,200.0
1,000.0
No. of Reports
120
100
800.0
80
600.0
60
400.0
40
200.0
20
0
0.0
Oct-08 Nov-08 Dec-08 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-09
Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09
Month-Year
Amantadine
Rimantadine
Oseltamivir
Zanamivir
Influenza Antiviral Rx's
*Up-to-date through 12/31/09 (DAWN) and 12/26/09 (BioSense). Note: AE data lagtime is 2-3 weeks.
No. of Prescriptions
(In Thousands)
140
Acknowledgments
• Taha Kass-Hout and BioSense staff
• CAPT Anthony Fiore, Influenza Division, CDC
• CDR Dan Budnitz, Division of Healthcare
Quality Promotion, CDC
Supplemental
Background on BioSense
• BioSense is a national program intended to improve
the nation’s capabilities for conducting real-time
biosurveillance, and enabling health situational
awareness through access to existing data from
healthcare organizations across the country
• BioSense receives, analyzes, and evaluates health data
from numerous data sources such as emergency
rooms, ambulatory care clinics, and clinical laboratories
• For more information:
– www.cdc.gov/biosense
– http://twitter.com/cdc_biosense
Location of BioSense Pharmacies (N≈27,000)
Antiviral AE Monitoring and Antiviral Dispensing, December 31, 2009