APPENDIX 22
Rotavirus
DISEASE BURDEN
Epidemiology
For the purposes of the calculations in this report, the committee estimated that there are approximately 3,500,000 new infections of rotavirus in the United States each year. It was assumed that all infections occur in infants and children between birth and 4 years of age and that the incidence in infants under 1 year of age (30,000 per 100,000) is twice that in children between 1 and 4 years of age. It was assumed that rotavirus infection leads to 100 deaths per year in the United States.
Disease Scenarios
For the purposes of the calculation in this report, the committee assumed that rotavirus infection is associated with 8 days of acute diarrhea and a health utility index of .75.
COST INCURRED BY DISEASE
Table A22–1 summarizes the health care costs incurred by rotavirus infections. For the purposes of the calculations in this report, it was assumed that all infants and children with rotavirus infection incur modest costs for over-the-counter treatment (e.g., oral rehydration) or extra diapers. It was also assumed
Table A22–1 Health Care Costs Associated with Rotavirus Infection
|
% with Care |
Cost per Unit |
Units per Case (or per year) |
Form of Treatment |
Acute diarrhea |
100% |
$10 |
2.0 |
oral rehydration therapy |
|
15% |
$50 |
1.0 |
physician a |
2% |
$2,000 |
1.0 |
hospitalization |
|
2% |
$150 |
1.0 |
physician c |
that 15% of infants and children receive medical attention. It is further assumed that a small percentage of children with rotavirus infection are hospitalized.
VACCINE DEVELOPMENT
The committee assumed that it would take 3 years until licensure of a rotavirus vaccine and that $120 million needed to be invested. During the time the committee report was in final stages of analysis and preparation, the rotavirus vaccine was approved for licensure. Table 4–1 summarizes vaccine development assumptions for all vaccines considered in this report.
VACCINE PROGRAM CONSIDERATIONS
Target Population
For the purposes of the calculations in this report, it is assumed that the target population for this vaccine is the annual birth cohort of infants. It was assumed that 90% of the target population would utilize the vaccine.
Vaccine Schedule, Efficacy, and Costs
For the purposes of the calculations in this report, it was estimated that this vaccine would cost $50 per dose and that administration costs would be $10 per dose. Default assumptions of a 3-dose series and 75% effectiveness were accepted. Table 4–1 summarizes vaccine program assumptions for all vaccines considered in this report.
RESULTS
If a vaccine program for rotavirus were implemented today and the vaccine were 100% efficacious and utilized by 100% of the target population, the annu-
alized present value of the QALYs gained would be 27,000. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the QALYs gained would be 14,000.
If a vaccine program for rotavirus were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the health care costs saved would be $225 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the health care costs saved would be $120 million.
If a vaccine program for rotavirus were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the program cost would be $720 million. Using committee assumptions of less-than-ideal efficacy and utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the program cost would be $510 million.
Using committee assumptions of time and costs until licensure, the fixed cost of vaccine development has been amortized and is $3.6 million for a rotavirus vaccine.
If a vaccine program were implemented today and the vaccine was 100% efficacious and utilized by 100% of the target population, the annualized present value of the cost per QALY gained is $20,000. Using committee assumptions of less-than-ideal utilization and including time and monetary costs until a vaccine program is implemented, the annualized present value of the cost per QALY gained is $30,000.
See Chapters 4 and 5 for details on the methods and assumptions used by the committee for the results reported.
During the time the data for this report was being analyzed and written, a rotavirus vaccine was licensed. The calculated cost per QALY saved for a vaccine strategy for a currently licensed rotavirus vaccine (assuming 75% effectiveness and 90% utilization and all other disease burden and costs as described above) decreases slightly to approximately $26,500.
READING LIST
Glass RI, Kilgore PE, Holman RC, et al. The Epidemiology of Rotavirus Diarrhea in the United States: Surveillance and Estimates of Disease Burden. The Journal of Infectious Diseases 1996; 174:S5–11.
Matson DO. Potential Impact of Rotavirus Vaccines. URL http://rotavirus.com/potential_impact_of_rota.html (accessed August 8, 1996).
Offit PA, Clark HF. Rotavirus. In: Principles and Practice of Infectious Diseases. GL Mandell, JE Bennett, Dolin R eds. New York, NY: Churchill Livingstone, 1995, pp. 1448–1455.
Orenstein WA, Hadler S, Kuritsky JN, et al. Rotavirus Vaccines—from Licensure to Disease Reduction. The Journal of Infectious Diseases 1996; 174:8118–24.
Smith JC, Haddix AC, Teutsch SM, et al. Cost-effectiveness Analysis of a Rotavirus Immunization Program for the United States. Pediatrics 1995; 96:609–615.
Ventura SJ, Martin JA, Mathews TJ, et al. Advance Report of Final Natality Statistics, 1994. Monthly Vital Statistics Report 1996; 44.