Table 5. Sensitivity analysis: impact of cost assumptions on the relative cost of semiannual/annual mass drug administration (MDA).
| Ratio of total program costs, with between brackets the estimated total program costs for semiannual over annual MDA (in US$ * 1000) | ||||||||
| Region | India | West Africa | ||||||
| Pre-control mf prevalence | 7.7% | 11.5% | 15% | 12.5% | 20% | 27.5% | ||
| No of MDA rounds required for elimination, semiannual/annual | 2/2 | 3/3 | 5/5 | 5/5 | 7/7 | 14/13 | ||
| Assumptions in cost calculations | ||||||||
| Discount rate (fraction) | Donated drugs cost | Purchasing drugs | ||||||
| 0.03a | excla | all eligiblesa | 0.90 (6.5/7.2) | 0.91 (9.6/10.6) | 0.92 (15.8/17.1) | 0.85 (49/58) | 0.86 (68/79) | 0.96 (130/136) |
| 0 | excl | all eligibles | 0.89 (6.5/7.3) | 0.89 (9.7/10.9) | 0.88 (16.1/18.2) | 0.82 (51/62) | 0.82 (71/87) | 0.88 (142/161) |
| 0.06 | excl | all eligibles | 0.92 (6.5/7.1) | 0.92 (9.5/10.3) | 0.95 (15.4/16.2) | 0.87 (48/55) | 0.90 (66/73) | 1.03 (120/116) |
| 0.03 | incl | all eligibles | 0.95 (10.9/11.5) | 0.95 (16.1/17.0) | 0.96 (26.5/27.5) | 1.03 (2112/2050) | 1.05 (2915/2789) | 1.17 (5549/4760) |
| 0.03 | excl | treated individuals only | 0.88 (6.0/6.8) | 0.90 (9.0/10.0) | 0.91 (14.8/16.2) | n.r. | n.r. | n.r. |
| 0.03 | incl | treated individuals only | 0.93 (9.5/10.1) | 0.94 (14.1/15.0) | 0.95 (23.1/24.2) | 1.03 (1748/1698) | 1.04 (2412/2311) | 1.16 (4592/3944) |
The values in the table are the ratio of total program costs, for semiannual MDA/annual MDA. This ratio shows which approach is less expensive (with values <1 indicating that semiannual MDA is less expensive and vice versa), and it provides an indication of the relative differences in cost. Between brackets, the total program costs estimates are given for semiannual/annual MDA programs, in 2009 US$ ×1000. Results are shown for Indian and West African settings, with varying pre-control mf prevalence levels. Coverage of MDA was assumed to be 70% per round (percentage of total population). The number of treatment rounds required for elimination differs between these settings (see table 4) and hence the total program costs. Given levels of mf prevalence are based on diagnosis with 60 µL blood smears.
n.r.: not relevant, because costs of drugs, which are all donated, are not included in the cost projections.
baseline assumptions.