A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | AA | AB | |
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1 | Insecticide resistance adjustment, not taking into account PBOs | Overall | DRC | Ghana | Malawi | PNG | Togo | Uganda | Zambia | Source / Notes | Link | |||||||||||||||||
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3 | Spending | $3,878,023 | $7,332,389 | $12,204,669 | $4,260,000 | $5,190,000 | $31,658,900 | $7,300,000 | GiveWell cost-effectiveness analysis (2018 - version 7) | https://docs.google.com/spreadsheets/d/1rszxDuWK3lu7cQBhXB3BOKnvYLrwd--iTVAqKznQ1mQ/edit#gid=1862644804 | ||||||||||||||||||
4 | Weight | 5% | 10% | 17% | 6% | 7% | 44% | 10% | GiveWell cost-effectiveness analysis (2018 - version 7) | https://docs.google.com/spreadsheets/d/1rszxDuWK3lu7cQBhXB3BOKnvYLrwd--iTVAqKznQ1mQ/edit#gid=1862644804 | ||||||||||||||||||
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6 | Mosquito mortality in pyrethroid 2010-16 (WHO insecticide susceptibility or CDC bottle bioassays using discriminating concentrations) | |||||||||||||||||||||||||||
7 | Sites tested | 12 | 46 | 70 | 4 | 5 | 21 | 109 | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
8 | Years | 2010-16 | 2010–2016 | 2010-15 | 2015 | 2011-13 | 2011-16 | 2011-16 | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
9 | Mean | 81% | 50% | 58% | 100% | 37% | 53% | 60% | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
10 | Min | 12% | 0% | 0% | 100% | 1% | 4% | 0% | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
11 | Max | 100% | 100% | 100% | 100% | 93% | 100% | 100% | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
12 | Mosquitoes tested | An. gambiae s.l. | An. coluzzii, An. funestus s.l., An. gambiae s.l. | An. arabiensis, An. funestus s.l., An. funestus s.s., An. gambiae s.l. | Anopheles spp. | An. gambiae s.l. | An. arabiensis, An. funestus s.l., An. gambiae s.l., An. gambiae s.s., An. parensis | An. funestus s.l., An. gambiae s.l., An. gambiae s.s. | WHO Global Report on insecticide resistance 2010-2016 (Annex 1) | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | ||||||||||||||||||
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15 | Change over time | |||||||||||||||||||||||||||
16 | 2010-16 | Annual | ||||||||||||||||||||||||||
17 | Increase in frequency West Africa | 5% | 0.83% | We use the estimated increase in median mortality to permethrin. "Trends analyses were conducted to determine whether there were any significant changes between 2010 and 2016 in malaria vector resistance to specific insecticides, and in specific vector groups (Fig. 4.4 and Fig. 4.5). A global increase in resistance frequency was observed for all pyrethroid insecticides tested. Increases were greatest for etofenprox (44% rise, from 7% to 51%), alphacypermethrin (40% rise, from 10% to 50%) and cyfluthrin (28% rise, from 4% to 32%). The increase was less pronounced for the other pyrethroids although these also had a higher initial resistance frequency in 2010: deltamethrin (14% rise, from 20% to 34%), permethrin (5% rise, from 40% to 45%) and lambda-cyhalothrin (3% rise, from 33% to 36%). This indicates that increasing resistance is an issue for all pyrethroids, and that reductions in susceptibility are most marked for those insecticides for which susceptibility was highest in 2010. Further evaluations will be undertaken to identify whether there are differences in resistance frequency and trends over time between insecticides of the pyrethroid class, in order to guide requirements for insecticide resistance monitoring. " Pg. 20 WHO Global Report on insecticide resistance 2010-2016 | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | |||||||||||||||||||||||
18 | Increase in frequency Central Africa | 5% | 0.83% | We use the estimated increase in median mortality to permethrin. "Trends analyses were conducted to determine whether there were any significant changes between 2010 and 2016 in malaria vector resistance to specific insecticides, and in specific vector groups (Fig. 4.4 and Fig. 4.5). A global increase in resistance frequency was observed for all pyrethroid insecticides tested. Increases were greatest for etofenprox (44% rise, from 7% to 51%), alphacypermethrin (40% rise, from 10% to 50%) and cyfluthrin (28% rise, from 4% to 32%). The increase was less pronounced for the other pyrethroids although these also had a higher initial resistance frequency in 2010: deltamethrin (14% rise, from 20% to 34%), permethrin (5% rise, from 40% to 45%) and lambda-cyhalothrin (3% rise, from 33% to 36%). This indicates that increasing resistance is an issue for all pyrethroids, and that reductions in susceptibility are most marked for those insecticides for which susceptibility was highest in 2010. Further evaluations will be undertaken to identify whether there are differences in resistance frequency and trends over time between insecticides of the pyrethroid class, in order to guide requirements for insecticide resistance monitoring. " Pg. 20 WHO Global Report on insecticide resistance 2010-2016 | http://apps.who.int/iris/bitstream/handle/10665/272533/9789241514057-eng.pdf?sequence=1&isAllowed=y | |||||||||||||||||||||||
19 | Increase in frequency East and Southern Africa | 5% | 0.83% | |||||||||||||||||||||||||
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21 | Expected annual increase (ppt) | 0.83% | 0.83% | 0.83% | 0% | 0.83% | 0.83% | 0.83% | Calculation | |||||||||||||||||||
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23 | Average year bioassays conducted | 2013 | 2013 | 2012.5 | 2015 | 2012 | 2013.5 | 2013.5 | Calculation | |||||||||||||||||||
24 | Current year | 2019 | 2019 | 2019 | 2019 | 2019 | 2019 | 2019 | Input | |||||||||||||||||||
25 | Years forecast out | 6 | 6 | 6.5 | 4 | 7 | 5.5 | 5.5 | Calculation | |||||||||||||||||||
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27 | Reduction in mosquito mortality | 5.00% | 5.00% | 5.42% | 0.00% | 5.83% | 4.58% | 4.58% | Calculation | |||||||||||||||||||
28 | ||||||||||||||||||||||||||||
29 | Mosquito mortality in 2019 | 76% | 45% | 53% | 100% | 31% | 48% | 55% | Calculation | |||||||||||||||||||
30 | Weighted average | 53% | ||||||||||||||||||||||||||
31 | ||||||||||||||||||||||||||||
32 | IR adjustment before accounting for PBO nets | |||||||||||||||||||||||||||
33 | Proportion of protection of LLIN due to physical barrier | 27% | 27% | 27% | 27% | 27% | 27% | 27% | See cell formulas to left for reference to calculation on "Insecticide vs Physical Barrier" sheet | |||||||||||||||||||
34 | Proportion of protection of LLIN due to pyrethroid | 73% | 73% | 73% | 73% | 73% | 73% | 73% | See cell formulas to left for reference to calculation on "Insecticide vs Physical Barrier" sheet | |||||||||||||||||||
35 | ||||||||||||||||||||||||||||
36 | Effectiveness of LLIN relative to Lengeler | 82% | 60% | 65% | 100% | 50% | 62% | 67% | Calculation | |||||||||||||||||||
37 | Reduction in effectiveness | 18% | 40% | 35% | 0% | 50% | 38% | 33% | Calculation | |||||||||||||||||||
38 | Weighted average | 34.45% | ||||||||||||||||||||||||||
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40 | Caveats, Limitations, Assumptions | |||||||||||||||||||||||||||
41 | Assumes 80% of effectiveness of LLINs scales linearly with mosquito mortality | |||||||||||||||||||||||||||
42 | The sites tested weren't random, or spatially distributed and mosquito mortality has a high variance, suggesting regional variation makes this very uncertain | |||||||||||||||||||||||||||
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44 | Evidence from PBO trial; testing the model that 80% of effectiveness of LLINs scales linearly with mosquito mortality | |||||||||||||||||||||||||||
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46 | Modelled results of PBO trial we would expect if 80% of effectiveness of LLINs scales linearly with mosquito mortality | |||||||||||||||||||||||||||
47 | Standard LLIN modelled effectiveness | |||||||||||||||||||||||||||
48 | Muleba mosquito mortality (permethrin alone) in study area | 10.50% | "Of the 13 689 Anopheline mosquitoes collected, 13 106 (95·7%) were A gambiae sensu lato and 510 (3·7%) were A funestus. Of the 990 A gambiae sensu lato identified to species, 946 (95·6%) were A gambiae sensu stricto and 44 (4·4%) were A arabiensis."; "The mortality of mosquitoes exposed to permethrin for resistance determination in the WHO cylinder tests was 8·8% (95% CI 5·3–12·3; n/N=54/613) for A gambiae sensu lato and 54·5% (36·8–76·2; n/N=59/108) for A funestus." Propopotoff et al. 2018 | https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(18)30427-6/fulltext | ||||||||||||||||||||||||
49 | Expected effectiveness of LLINs relative to Lengeler | 35% | Based on model of 80% of effectiveness of LLINs scales linearly with mosquito mortality | |||||||||||||||||||||||||
50 | Standard LLIN Incidence risk reduction (ITT) (i.e. 1 - risk ratio) from Lengeler | 0.5 | "ITNs reduced the incidence of uncomplicated malarial episodes in areas of stable malaria by 50% compared to no nets, and 39% compared to untreated nets" Lengeler 2004 | https://www.ncbi.nlm.nih.gov/pubmed/15106149 | ||||||||||||||||||||||||
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52 | Standard LLIN Incidence risk reduction (vs no nets) we would expect | 0.17 | ||||||||||||||||||||||||||
53 | Standard LLIN relative risk (vs no nets) we would expect | 0.83 | ||||||||||||||||||||||||||
54 | ||||||||||||||||||||||||||||
55 | PBO nets modelled effectiveness | |||||||||||||||||||||||||||
56 | Muleba mosquito mortality (permethrin + PBO) in study area | 93.50% | Matowo et al. 2015 | https://www.ncbi.nlm.nih.gov/pubmed/25537754 | ||||||||||||||||||||||||
57 | Expected effectiveness of PBOs relative to Lengeler | 95.26% | ||||||||||||||||||||||||||
58 | ||||||||||||||||||||||||||||
59 | PBO LLIN Incidence risk reduction vs no nets we would expect | 0.4762820815 | ||||||||||||||||||||||||||
60 | PBO LLIN relative risk vs no nets we would expect | 0.5237179185 | ||||||||||||||||||||||||||
61 | ||||||||||||||||||||||||||||
62 | Is this model consistent with the results from Propopotoff et al. 2018? | |||||||||||||||||||||||||||
63 | Relative risk of PBO vs standard LLINs we'd expect (ITT) | 0.63 | ||||||||||||||||||||||||||
64 | Relative risk of PBO vs standard LLINs we observe (ITT) | 0.68 | ||||||||||||||||||||||||||
65 | ||||||||||||||||||||||||||||
66 | Conclusions | |||||||||||||||||||||||||||
67 | The model is broadly consistent with the results we saw from Propopotoff et al. 2018 | |||||||||||||||||||||||||||
68 | ||||||||||||||||||||||||||||
69 | Insecticide resistance adjustment, taking into account PBOs | |||||||||||||||||||||||||||
70 | ||||||||||||||||||||||||||||
71 | Proportion of pyrethroid-resistant mosquitos which are also resistant to PBO | 7% | ||||||||||||||||||||||||||
72 | Insecticide resistance adjustment in areas covered by PBOs | 2.50% | ||||||||||||||||||||||||||
73 | ||||||||||||||||||||||||||||
74 | Insecticide resistance adjustment incorporating PBOs | 24.87% | ||||||||||||||||||||||||||
75 | ||||||||||||||||||||||||||||
76 | Caveats, Limitations, Assumptions | |||||||||||||||||||||||||||
77 | We have used the ITT effect from Propopotoff et al. 2018, with no adjustment for differing levels of coverage (i.e. nets that end up being used) between AMF's programs and Propopotoff et al. 2018 | |||||||||||||||||||||||||||
78 | We have assumed AMF will distribute PBO nets rather than standard LLINs roughly in proportion to levels of mosquito mortality | |||||||||||||||||||||||||||
79 | ||||||||||||||||||||||||||||
80 | What level of mosquito mortality would mean PBO nets are more cost-effective than standard LLINs? | |||||||||||||||||||||||||||
81 | Cost of PBO | $2.00 | Givewell cost-effectiveness analysis, August 2018 | |||||||||||||||||||||||||
82 | Cost of standard LLIN | $2.40 | Givewell cost-effectiveness analysis, August 2018 | |||||||||||||||||||||||||
83 | ||||||||||||||||||||||||||||
84 | Non-net costs | $2.43 | Givewell cost-effectiveness analysis, August 2018 | |||||||||||||||||||||||||
85 | ||||||||||||||||||||||||||||
86 | How much more does delivering a PBO net cost? | 9.03% | ||||||||||||||||||||||||||
87 | ||||||||||||||||||||||||||||
88 | How much more effective should a PBO net be to justify this additional cost? | 9.03% | ||||||||||||||||||||||||||
89 | ||||||||||||||||||||||||||||
90 | Proportion of protection of LLIN due to physical barrier | 27% | ||||||||||||||||||||||||||
91 | Proportion of protection of LLIN due to pyrethroid | 73% | ||||||||||||||||||||||||||
92 | ||||||||||||||||||||||||||||
93 | What reduction in mosquito survival do we expect from using PBO, rather than permethrin alone? | 92.74% | ||||||||||||||||||||||||||
94 | ||||||||||||||||||||||||||||
95 | What is mosquito mortality with permethrin? | 90% | Sensitivity input - arbitrary | |||||||||||||||||||||||||
96 | What is mosquito mortality with PBO? | 99% | ||||||||||||||||||||||||||
97 | ||||||||||||||||||||||||||||
98 | How much more effective is PBO than a standard LLIN? | 8% | ||||||||||||||||||||||||||
99 | ||||||||||||||||||||||||||||
100 | How much more cost-effective is PBO than a standard LLIN? | 1% |