TABLE A-1
Stationary Population Process Model for Population Age j at Year i
Measure |
Formulation |
1. Population Size (N) |
For year i = 1: Nij = age – specific population size For year i > 1: Nij = Ni-1,j-1 – DWi-1,j-1 – CPi-1,j-1 |
2. Target Population (T) |
No Vaccine: Tij = Nij × Proportion Targetij where Proportion Targetij = 0 Vaccine Steady State for year i = 1: Tij = Nij × Proportion Targetij where Proportion Targetij = 1 Vaccine Introduced: Tij = Nij × Proportion Targetij with Proportion Targetij = Input (% of N)ij |
3. Vaccinated Immune (V) |
Vij = Tij × coverage rateij × effectivenessij |
4. Vaccinated Susceptible (VS) |
VSij = Tij × coverage rateij × (1 – effectivenessij) |
5. Not Vaccinated Immune (B) |
Bij = (Vij / herd immunityij) – Vij |
6. Not Vaccinated Susceptible (BS) |
BSij = Nij – Vij – VSij – Bij |
7. Total Cases (C) |
Cij = (VSij + BSij) × incidence rate |
8. Deaths by Disease (D) |
Dij = Cij × case fatality rate |
Measure |
Formulation |
9. Cases: Impairment (CP) |
CPij = (Cij – Dij) × proportion cases impaired |
10. Cases: Morbidity (CM) |
CMij = Cij – Dij – CPij |
11. Vaccine Complications (A) |
Aij = (Vij + VSij) × vaccine complications rate |
12. All Cause Deaths (DA) Including Disease |
No Vaccine: DAij = Nij × all cause mortality rate Vaccine Steady State: DAij = (Nij × all cause mortality rate) – Deaths averted by vaccine * Deaths averted by vaccine = Vaccine Steady State Dij – No Vaccine Dij Vaccine Introduced: DAij = (Nij × all cause mortality rate) – Deaths averted by vaccine * Deaths averted by vaccine = Vaccine Introduced Dij – No Vaccine Dij |
13. Cause Deleted Deaths (DE) Excluding Disease |
DEij = DAij – Dij |
TABLE A-2
Health and Economic Values for Population Age j at Year i
1. Premature Deaths Averted per Year |
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2. Incident Cases Prevented per Year |
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3. Quality-Adjusted Life Years (QALYs) Gained |
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4. Disability-Adjusted Life Years (DALYs) Gainedaa |
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5. Net Direct Costs |
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6. Delivery Costs |
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7. Health Care Costs (HC) Averted |
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8. Workforce Productivity (WP) Gained per Year |
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9. One-Time Costs |
Cost Research + Cost Licensure + Cost Start Up |
aFox-Rushby, J. A., and Hanson, K. 2001. Calculating and presenting disability-adjusted life years (DALYs) in cost-effectiveness analysis. Health Policy and Planning 16(3):326-331.
TABLE A-3
Detailed Expressions (in Reference to Table A-1 and Table A-2)
Measure |
Formulation |
|
All Cause Mortality Rate (Derived by Life Table Over Interval)a |
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QALYsDeath |
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QALYsImpairment by disease or complication |
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QALYsMorbidity by disease or complication |
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Disability-Adjusted Life Years (DALYs) Generalizationb |
Years of Life Lost (YLL) + Years of Life Lived with Disability (YLD) |
|
YLD or YLL (W = 1) |
||
DALYs Variables |
K = age weight modulation factor (0 = off, 1 = on) F = constant (0.1658) r = discount rate j = age of death (YLL) or age of onset of disability (YLD) G = parameter form the age weighting function (0.04) L = standard expectation of life at age a (YLL) or duration of disability (YLD) W = disability weight (YLD) |
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DALYsDeath |
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DALYsImpairment by disease or complication |
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DALYsMorbidity by disease or complication |
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Health Care Costs (HC)Death |
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HCImpairments by disease or complication |
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HCMorbidity by disease or complication |
Measure |
Formulation |
|
Workforce Productivity (WP) Gained DeathDeath |
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WPImpairment by disease or complication |
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WPMorbidity by disease or complication |
aPreston, S., P. Heuveline, and M. Guillot. 2000. Demography: Measuring and modeling population processes. Chapter 3: The Life Table and Single Decrement Process. P. 46.
bFox-Rushby, J. A., and K. Hanson. 2001. Calculating and presenting disability adjusted life years (DALYs) in cost-effectiveness analysis. Health Policy and Planning 16(3):326–331.