Sightsavers — Support for Deworming in Kaduna, Zamfara, Niger, Kano, Adamawa, and Katsina in 2021-2023 (October 2021)


In October 2021, GiveWell recommended that Open Philanthropy grant $4.4 million to Sightsavers to support mass drug administration for schistosomiasis and soil-transmitted helminths (deworming) in six states in Nigeria in 2021-2023. Sightsavers’ deworming program is one of GiveWell's top charities.

We recommended this grant because we believe that Sightsavers' work to support deworming in these states will be cost-effective. Based on its track record, we believe that Sightsavers is well-positioned to execute the activities funded by this grant.

Published: December 2021

Table of Contents

Planned activities and budget

The $4.4 million grant will support deworming from late 2021 through late 2022 (or early 2022 through early 2023)1 in areas requiring deworming according to WHO-defined prevalence thresholds in six states: Kaduna, Zamfara, Niger, Kano, Adamawa, and Katsina.2 The cost per state per year, before an expected ~10% budget increase due to additional costs associated with delivering this program in the context of the COVID-19 pandemic, ranges from $205,000 to $600,000. See here for more details of the budget breakdown.

We typically recommend three-year grants because grantees have told us in the past that there are often substantial benefits to knowing that funding for a program is secure for the future.3 For this grant we have recommended 1.5 years (two rounds of deworming) to allow for more time to understand the long-term funding landscape for deworming in Nigeria.

For more detail on grant activities, see Sightsavers' proposal here.

The case for the grant

  • We consider this program to be cost-effective. More below.
  • Previously, this work was part of a broader neglected tropical diseases (NTDs) program funded by the UK government. A funding gap for this work emerged unexpectedly when the government ended that program a year earlier than planned.4 Though some other resources became available to fund some of the activities that had been supported through the program, there was not enough funding to fully replace the UK government's budget, and funding gaps remain. More below.
  • We believe that Sightsavers is well-positioned to support this work. It has extensive experience supporting deworming in Nigeria (and other countries) and has recently been supporting deworming and mass drug administration for other NTDs in these six states. More below.


A note on how we discuss cost-effectiveness on this page

We often use GiveDirectly’s unconditional cash transfers as a benchmark for comparing the cost-effectiveness of different programs. When discussing cost-effectiveness, we generally refer to the cost-effectiveness of a program in multiples of "cash." Thus, if a program is estimated to be "10x cash," this means it is estimated to be ten times as cost-effective as unconditional cash transfers.

Cost-effectiveness of this grant

Based on our cost-effectiveness analysis of deworming in these six states, we believe the program is in the range of cost-effectiveness of programs we expect to direct funding to, as of 2021. Our estimate is that deworming in these states ranges from 10x to 60x cash.5 We estimate that the overall cost-effectiveness of this grant is 35x cash.6 At the time we recommended this grant, we were primarily looking to recommend grants that we estimated were 8x cash or higher, and were willing to consider recommending a limited amount of funding to grants that were between 5x and 8x cash.

Note that our cost-effectiveness analyses are simplified models that do not take into account a number of factors. There are limitations to this kind of cost-effectiveness analysis, and we believe that cost-effectiveness estimates such as these should not be taken literally due to the significant uncertainty around them. We provide these estimates (a) for comparative purposes to other grants we have made or considered making, and (b) because working on them helps us ensure that we are thinking through as many of the relevant issues as possible. In addition, our process for estimating cost-effectiveness focuses on determining whether a program is cost-effective enough that it is above our threshold to consider funding; it isn't primarily intended to differentiate between values that are above that threshold.

Our cost-effectiveness analysis for this grant is based on the same structure as our model for other deworming grants. While investigating this grant, we updated parameters within that model to use inputs specific to this funding gap. Below, we highlight parameters that vary for different funding gaps and have a substantial impact on our headline cost-effectiveness figures:

  • Worm burden: For every deworming grant, we ask the potential grantee to provide data on the prevalence and/or intensity of infections with each species of schistosomiasis and soil-transmitted helminths in the locations where they would support deworming. We prefer to use data on the prevalence of moderate-intensity infections and of heavy-intensity infections for each species. When this isn't available, we use average intensity of infection or prevalence of any infection. We then apply an adjustment to our cost-effectiveness estimates of deworming programs to account for differences between the prevalence and intensity of worm infections in the geographies targeted by our deworming grantees and the prevalence and intensity of worm infections among the population studied in Miguel and Kremer 2004 the randomized controlled trial (RCT) on which we base our estimate of deworming's impact on consumption. Worm burden varies a lot among the states supported by this grant, and consequently so does this adjustment: from 4% of the level during the RCT to 20%.7 This is the driver of differences in cost-effectiveness across the states in our model.
  • Cost per child dewormed: We estimated that, on average, the total cost per child dewormed per year in all six states will be $0.92.8 We generated this estimate by comparing Sightsavers' budgeted cost for these six states with estimates of the treatment-eligible population within those states. To this, we added estimated costs incurred by the government and the value of drug donations to get an estimate of total cost. Another option we considered was to use the average cost per child that has been achieved in the other states in Nigeria where we have previously supported Sightsavers work on deworming ($0.68, before adding in government costs and drug donations),9 based on a hypothesis that past actuals might provide a more reliable indication of future costs. However, because the past average was significantly lower than the projected cost based on the budget, we ultimately decided to use the higher value. This decision was based on a guess that this higher value may capture reasons why Sightsavers believes that costs will be higher in the six states than in the states we've supported previously, though we have not asked Sightsavers for those reasons.

Funding landscape for deworming in Nigeria

Deworming in these six states was previously funded by the UK's Foreign, Commonwealth & Development Office (FCDO) under the Accelerating the Sustainable Control and Elimination of Neglected Tropical Diseases (ASCEND) program.10 FCDO ended the ASCEND program in 2021, 8-12 months earlier than expected,11 citing "a challenging financial climate as a result of COVID."12

Children's Investment Fund Foundation (CIFF), the Bill & Melinda Gates Foundation (BMGF), and ELMA Philanthropies have pledged funding to support some of the programs that were previously funded by ASCEND, including some deworming programs and some programs treating other NTDs.13 We began discussing the deworming funding gap in these six states in Nigeria with Sightsavers before we heard about these other funders' plans. It is possible that one of these funders would have funded this gap if we had not already indicated to Sightsavers, and in conversation with ELMA Philanthropies, that it might fit our criteria. If they had done so, that likely would have left another NTD funding gap elsewhere, as these funders have not pledged sufficient funds to fully replace ASCEND. This means that one effect of us making this grant may have been to push funding that would have supported this work into a different NTD program; we don't know which NTD or location would have received this funding.

We are not aware of other major funders who would consider deworming in Nigeria to be a priority and therefore might have funded this work. This understanding comes from many conversations—we have followed the deworming funding space for over ten years and funded deworming in other states in Nigeria in the past.

Sightsavers' track record

We have previously funded Sightsavers to support deworming in seven other states in Nigeria.14 Coverage surveys conducted after GiveWell-funded deworming mass drug administration (MDA) in 201815 and 201916 generally found high coverage of school-aged children, with most local government areas (LGAs) surveyed achieving 75% coverage (the WHO-recommended minimum threshold)17 or higher.18

Risks and reservations

  • The NTD funding landscape is changing rapidly. With FCDO's earlier-than-expected exit from funding NTDs and the increase in funding from other funders to make up some of the shortfall, it is currently more difficult than usual to predict the extent to which we are crowding out other funders. As stated above, we have consequently chosen to recommend a 1.5 year grant instead of our standard three-year grant. We think this approach will enable us to fill an immediate gap, such that deworming rounds are not skipped in these states, while also giving us more time to coordinate with other funders and learn about the long-term funding landscape for deworming in Nigeria before making a longer commitment.
  • There are many parameters in our cost-effectiveness model about which we have substantial uncertainty, but we have often come back to the worm burden adjustment as one in particular that we'd like to improve because it is the primary driver of differences in cost-effectiveness across deworming programs. Our goal is for the worm burden data we use in this adjustment to be as representative as possible of the areas a program will support. We believe that we could do more to accomplish this goal by examining the specific methods used in each survey of worm burden that we rely on, as many different methods have been used across time and locations. If we were to do more on this, we might make additional adjustments for the extent to which a survey is representative of the area where we'd support deworming, how long ago the survey was conducted, how many rounds of deworming were conducted before and since the survey, and other factors. For this grant, we did a light review of the methodology used to measure worm burden in the six states and felt reasonably confident that the results were representative of the areas the grant will support.

Plans for follow up

In 2022 and 2023, we expect to get updates from Sightsavers on total spending in each of these six states and results of coverage surveys in each state. We plan to use this data to update our estimate of the cost-effectiveness of deworming in these states. We also expect to have some conversations to update our understanding of the funding landscape for deworming in Nigeria.

Internal forecasts

Confidence Prediction By time
50% Conditional on our doing the analysis, once we have updated our cost-effectiveness model for this grant with actual spending and numbers of children reached, we will conclude that the grant was as cost-effective or more cost-effective than we modeled before making the grant. End of 2023

Our process

After FCDO announced that it was ending the ASCEND project under which it had funded Sightsavers to deliver MDA for several NTDs in a set of countries primarily in western Africa, Sightsavers asked if GiveWell would consider replacing the portion of that funding that was supporting deworming in Nigeria.19 Sightsavers provided information about the funding gap, treatment plans, worm burden, and budget.20

Sightsavers initially included Borno and Lagos states in the proposal as well. We decided not to recommend funding for Borno, because at the time of this grant decision, we lacked worm burden data for the state (Sightsavers shared this data with us in November 2021). We decided not to recommend funding for Lagos, because another grantee we support, Evidence Action's Deworm the World Initiative, has been supporting deworming in part of Lagos and told us that it is positioned to support it in the rest of the state.21

In addition to Sightsavers, during the process of determining whether to recommend this grant, we spoke to the NTD Coordinators (government officials who manage NTD programs at the state level) in Niger and Kaduna states, and with representatives of CIFF, ELMA Philanthropies, END Fund, Helen Keller International's Nigeria NTDs team (a sub-grantee of Sightsavers for two of the states supported by this grant), HANDS (a sub-grantee of Sightsavers for one state), and Evidence Action's Deworm the World Initiative (see note above about support for Lagos). We greatly appreciate their contributions to this grant decision. The conclusions described in this page, and any errors, are our own.


Document Source
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Miguel and Kremer 2004 Source (archive)
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World Health Assembly, "Schistosomiasis and soil-transmitted helminth infections," 2001 Source (archive)
World Health Organization, "Schistosomiasis and soil-transmitted helminthiases: number of people treated in 2018," 2019 Source (archive)