Table 6 Sensitivity analysis of vaccine strategies for tuberculosis control in Zambia, for the total cohort of 468,073 newborns
From: Cost-effectiveness of novel vaccines for tuberculosis control: a decision analysis study
Parameter Varied | No. of TB cases prevented* | Change in Direct Costs†$ million | Change in Indirect Costs†$ million | Change in Total Costs†$ million |
|---|---|---|---|---|
| Â | All values are relative to the status quo strategy over 30 years | |||
Novel TB Vaccine at Birth | Â | Â | Â | Â |
   Base case (no change in parameters) | 932 | ($0.25) | ($3.37) | ($3.62) |
   Initial investment doubled | 932 | $0.31 | ($3.37) | ($3.06) |
   Initial investment quadrupled | 932 | $1.44 | ($3.37) | ($1.93) |
   Vaccine unit costs doubled | 932 | $0.24 | ($3.37) | ($3.13) |
   Vaccine unit costs quadrupled | 932 | $1.20 | ($3.37) | ($2.17) |
   Initial investment & vaccine unit costs doubled | 932 | $0.79 | ($3.37) | ($2.58) |
   Initial investment & vaccine unit costs quadrupled | 932 | $2.89 | ($3.37) | ($0.48) |
   Vaccine duration of action halved (5 yrs) | (98) | $0.22 | $0.33 | $0.55 |
   Initial investment & vaccine unit costs doubled & vaccine duration of action halved | (98) | $1.26 | $0.33 | $1.59 |
   HIV prevalence increased by 50% | 1,020 | ($0.28) | ($3.57) | ($3.85) |
   HIV prevalence decreased by 50% | 833 | ($0.23) | ($3.16) | ($3.39) |
   Annual risk of TB infection increased by 50% | 1,297 | ($0.41) | ($4.67) | ($5.08) |
   Annual risk of TB infection decreased by 50% | 501 | ($0.06) | ($1.83) | ($1.89) |
   Discount rate 2% annually | 936 | ($0.26) | ($3.79) | ($4.05) |
   Discount rate 6% annually | 899 | ($0.23) | ($2.46) | ($2.69) |
Novel TB Vaccine at Birth with Booster | Â | Â | Â | Â |
   Base case (no change in parameters) | 1,863 | $0.55 | ($6.16) | ($5.61) |
   Initial investment doubled | 1,863 | $1.33 | ($6.16) | ($4.83) |
   Initial investment quadrupled | 1,863 | $2.87 | ($6.16) | ($3.29) |
   Vaccine unit costs doubled | 1,863 | $2.05 | ($6.16) | ($4.11) |
   Vaccine unit costs quadrupled | 1,863 | $5.05 | ($6.16) | ($1.11) |
   Initial investment & vaccine unit costs doubled | 1863 | $2.82 | ($6.16) | ($3.34) |
   Initial investment & vaccine unit costs quadrupled | 1,863 | $7.36 | ($6.16) | $1.20 |
   Vaccine duration of action halved (5 yrs) | 904 | $0.98 | ($3.18) | ($2.20) |
   Initial investment & vaccine unit costs doubled & vaccine duration of action halved | 904 | $3.25 | ($3.18) | $0.07 |
   HIV prevalence increased by 50% | 1,994 | $0.53 | ($6.48) | ($5.95) |
   HIV prevalence decreased by 50% | 1,718 | $0.58 | ($5.81) | ($5.23) |
   Annual risk of TB infection increased by 50% | 2,294 | $0.37 | ($7.64) | ($7.27) |
   Annual risk of TB infection decreased by 50% | 1,151 | $0.87 | ($3.78) | ($2.91) |
   Discount rate 2% annually | 1,985 | $0.59 | ($7.15) | ($6.56) |
   Discount rate 6% annually | 1,568 | $0.45 | ($4.09) | ($3.64) |