Archive for October 6, 2009

Effectiveness and Cost-Effectiveness of Vaccination Against Pandemic Influenza (H1N1) 2009

Ann of Inter Med. 05  Oct  2009  V.151 N.12

Nayer Khazeni, MD, MS; David W. Hutton, MS; Alan M. Garber, MD, PhD; Nathaniel Hupert, MD, MPH; and Douglas K. Owens, MD, MS

From Stanford University Medical Center and Stanford University, Stanford, California; Veterans Affairs Palo Alto Health Care System, Palo Alto, California; and Cornell Medical College, New York, New York.

Background: Decisions on the timing and extent of vaccination against pandemic (H1N1) 2009 virus are complex.

Objective: To estimate the effectiveness and cost-effectiveness of pandemic influenza (H1N1) vaccination under different scenarios in October or November 2009.

Design: Compartmental epidemic model in conjunction with a Markov model of disease progression.

Data Sources: Literature and expert opinion.

Target Population: Residents of a major U.S. metropolitan city with a population of 8.3 million.

Time Horizon: Lifetime.

Perspective: Societal.

Interventions: Vaccination in mid-October or mid-November 2009.

Outcome Measures: Infections and deaths averted, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness.

Results of Base-Case Analysis: Assuming each primary infection causes 1.5 secondary infections, vaccinating 40% of the population in October or November would be cost-saving. Vaccination in October would avert 2051 deaths, gain 69 679 QALYs, and save $469 million compared with no vaccination; vaccination in November would avert 1468 deaths, gain 49 422 QALYs, and save $302 million.

Results of Sensitivity Analysis: Vaccination is even more cost-saving if longer incubation periods, lower rates of infectiousness, or increased implementation of nonpharmaceutical interventions delay time to the peak of the pandemic. Vaccination saves fewer lives and is less cost-effective if the epidemic peaks earlier than mid-October.

Limitations: The model assumed homogenous mixing of case-patients and contacts; heterogeneous mixing would result in faster initial spread, followed by slower spread. Additional costs and savings not included in the model would make vaccination more cost-saving.

Conclusion: Earlier vaccination against pandemic (H1N1) 2009 prevents more deaths and is more cost-saving. Complete population coverage is not necessary to reduce the viral reproductive rate sufficiently to help shorten the pandemic.

Primary Funding Source: Agency for Healthcare Research and Quality and National Institute on Drug Abuse.

Abstract

http://www.annals.org/cgi/content/abstract/0000605-200912150-00157v1?papetoc

Full Text

http://www.annals.org/cgi/content/full/0000605-200912150-00157v1

October 6, 2009 at 11:24 am Leave a comment

Effectiveness and Cost-Effectiveness of Expanded Antiviral Prophylaxis and Adjuvanted Vaccination Strategies for an Influenza A (H5N1) Pandemic

Ann of Inter Med. 05  Oct  2009  V.151  N.2

Nayer Khazeni, MD, MS; David W. Hutton, MS; Alan M. Garber, MD, PhD; and Douglas K. Owens, MD, MS

From Stanford University and Stanford University Medical Center, Stanford, California, and Veterans Affairs Palo Alto Health Care System, Palo Alto, California

Background: The pandemic potential of influenza A (H5N1) virus is a prominent public health concern of the 21st century.

Objective: To estimate the effectiveness and cost-effectiveness of alternative pandemic (H5N1) mitigation and response strategies.

Design: Compartmental epidemic model in conjunction with a Markov model of disease progression.

Data Sources: Literature and expert opinion.

Target Population: Residents of a U.S. metropolitan city with a population of 8.3 million.

Time Horizon: Lifetime.

Perspective: Societal.

Interventions: 3 scenarios: 1) vaccination and antiviral pharmacotherapy in quantities similar to those currently available in the U.S. stockpile (stockpiled strategy), 2) stockpiled strategy but with expanded distribution of antiviral agents (expanded prophylaxis strategy), and 3) stockpiled strategy but with adjuvanted vaccine (expanded vaccination strategy). All scenarios assumed standard nonpharmaceutical interventions.

Outcome Measures: Infections and deaths averted, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness.

Results of Base-Case Analysis: Expanded vaccination was the most effective and cost-effective of the 3 strategies, averting 68% of infections and deaths and gaining 404 030 QALYs at $10 844 per QALY gained relative to the stockpiled strategy.

Results of Sensitivity Analysis: Expanded vaccination remained incrementally cost-effective over a wide range of assumptions.

Limitations: The model assumed homogenous mixing of cases and contacts; heterogeneous mixing would result in faster initial spread, followed by slower spread. We did not model interventions for children or older adults; the model is not designed to target interventions to specific groups.

Conclusion: Expanded adjuvanted vaccination is an effective and cost-effective mitigation strategy for an influenza A (H5N1) pandemic. Expanded antiviral prophylaxis can help delay the pandemic while additional strategies are implemented.

Primary Funding Source: National Institutes of Health and Agency for Healthcare Research and Quality

Abstract

http://www.annals.org:80/cgi/content/abstract/0000605-200912150-00156v1?papetoc

Full Text

http://www.annals.org/cgi/content/full/0000605-200912150-00156v1

October 6, 2009 at 11:22 am Leave a comment


Calendar

October 2009
M T W T F S S
 1234
567891011
12131415161718
19202122232425
262728293031  

Posts by Month

Posts by Category