John Halstead

The Best Public Health Interventions of the 20th Century

Public health interventions in the 20th century have been responsible for massive improvements in global health. According to the Copenhagen Consensus,

“Life expectancy hardly changed before the late 18th century. Yet it is hard to overstate the magnitude of the improvement since 1900, from a life expectancy of 32 years to 69 now, to 76 in 2050. The biggest factor was the fall in infant mortality.”[1]

68% of the improvement in human health is down to technical improvements, such as vaccines, micronutrient fortification and deworming medicine, while higher income accounts for only 3%. For example, Sub-Saharan Africa’s real per capita income in 2008 was just over half that of England in 1870, and yet child mortality rates are two thirds lower in Africa in 2008 than in England around 1870.[2]

Under five Years of Life Lost (YLL) as a percentage of total YLL 1990 – 2050.[3]

Many critics of aid[4] underestimate the sheer scale of the progress that has been achieved as a result of public health interventions, which are often supported by foreign aid and international bodies such as the World Health Organization (WHO), UNICEF and the World Bank. In this blogpost, I will briefly describe and assess some of the most successful public health interventions of the 20th century.

This research relies to a large extent on the prior work done in this area by the Centre for Global Development, which has been published as Millions Saved. We have selected four of the twenty case studies from Millions Saved, examined the evidence given, and tried to provide reasonable estimates of cost-effectiveness. In addition, we look at an intervention not covered in Millions Saved – reducing tuberculosis in south east Africa.

We have strong reason to believe that that all of the interventions had high impact and very high cost-effectiveness.[5] All of them averted a Disability Adjusted Life Year (DALY)[6] for less than $50, some of them significantly less, with smallpox eradication, for example, saving a life (30-40 years) for $5. For context: the NHS will spend £30,000 to save a Quality-Adjusted Life Year (QALY);[7] and the world’s most effective charities avert a DALY for around $30.[8]

The smallpox eradication campaign (1967-1979) is by some distance the most effective program considered here and is one of the best public health interventions of all time. In 1967, smallpox affected 10-15m people and killed nearly a quarter of them.[9] The eradication campaign, with the help of the WHO, the US government and endemic countries cost only $300m.[10] It has saved at least 50m lives until today and provided enormous non-life-saving health benefits.[11]

Cost per life saved (1967-2014) = $5 per life.

This suggests that the intervention averted a DALY for significantly less than $1. Indeed, the benefits mentioned here do not include non-life-saving health benefits, such as blindness prevented. The eradication of smallpox was a truly extraordinary public health achievement.

2. Guinea worm reduction in Asia and Sub-Saharan Africa

Giving What We Can views interventions against Neglected Tropical Disease (NTDs) as having high cost-effectiveness.[12] One NTD, which until recently blighted much of Africa, is dracunculiasis AKA ‘guinea worm disease’. Guinea worm is contracted by drinking water bearing the guinea worm parasite. The disease is rarely fatal, but it does impose a significant disability and pain burden on those infected. On average, the disease incapacitates people for 8.5 weeks.[13]

In 1986, the WHO passed a resolution to eradicate guinea worm within 10 years.[14] In close collaboration with UNICEF, the US Centres for Disease Control and Prevention (CDC) and the WHO, the Carter Centre led the eradication effort.[15] To reduce the burden of the disease, the campaign encouraged the provision of safe water and water filtering through cloth, health education, surveillance of new cases and case containment.[16]

In 1986, there were around 3.5m cases of guinea worm worldwide. Today, guinea worm is very nearly eliminated, with fewer than 200 reported cases in 2013.[18] We provide the following estimate of cost-effectiveness:

Cost per DALY averted (1986-2004) = $46.20.[19]

According to Givewell, the global program to eradicate guinea worm is ‘one of the success stories of global health’.[20]

In Egypt in 1978 all cause infant mortality was exceptionally high at 100 per 1000 live births, which meant that more than 100,000 infants died every year. At least half of these deaths were diarrhoea associated.[21] In the 1960s, it was discovered that diarrhoea could be treated effectively with a simple combination of salt, sugar and water, called Oral Rehydration Therapy (ORT).[22]

The Egyptian National Control of Diarrheal Disease Project (NCDDP), introduced in 1981, improved case management of diarrhoea through ORT and better feeding, especially breastfeeding.[24]

There is good evidence to show that ORT significantly reduced infant mortality in Egypt. From 1970-77, the reduction in infant mortality attributable to diarrhoea was 4.2%; from 1977-82 it was 7.8%; whereas from 1982-90 – the peak years of the NCDDP – it was 15.9%.[25] The rate of infant diarrhoeal deaths declined faster than the overall rate of infant mortality after the introduction of the NCDDP.

We conservatively estimate that the programme saved 100,000 lives in the 1980s.[26] According to the Centre for Global Development, the program cost $43m. It was funded by USAID and the Egyptian government and with assistance provided by UNICEF and the WHO.[27] So, we estimate that the program saved a life for $43m/100,000.

This is exceptional. According to a paper in the British Medical Journal, ORT saved 50 million lives worldwide in the 20th century.[28]

4. Controlling tuberculosis in south east Africa

In 2012, 8.6m people fell ill with tuberculosis (TB) and 1.3m of them died (including 320,000 deaths from HIV positive people). In Malawi, Tanzania and Mozambique, national tuberculosis control programmes making use of short-course chemotherapy proved a highly cost-effective tool in the battle against TB.

TB is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs. It is highly contagious.[29] Efforts to control TB have been significantly setback by the rise of HIV in the 1980s and 90s, as the two infections co-exist in large numbers of people. In the mid 1960s new drugs were discovered which allowed short-course chemotherapy treatment. This was testimony to the wisdom of the British Medical Research Council, which provided long-term support for tuberculosis research.[30]

In the 1980s, short-course chemotherapy was introduced and rapidly expanded in Malawi, Tanzania and Mozambique.[31] In all three countries, the cure rate for short-course chemotherapy ranged from 70% In Mozambique to 87% in Malawi, whereas the average cure rate for standard chemotherapy was 40-50%.[32] Despite the impact of the HIV outbreak on TB death rates, the chemotherapy cure rate remained largely unaffected by the HIV outbreak.[33] According to De Jonghe et al, the average cost-effectiveness of the intervention was:

Cost per year of life saved = <$6< big="">

According to the WHO, an estimated 37m lives were saved by tuberculosis treatment from 2000-2013.[34] As the tuberculosis situation improves in the developed world, it is nonetheless deteriorating in the developing world.[35] We hope that in the future, the poor will be able to afford the same healthcare resources as the rich today.

5. Preventing Iodine Deficiency Disease in China

Iodine Deficiency Disorder (IDD) is the world’s leading, and most easily preventable, cause of mental illness, with around 50m sufferers today.[36] In severe cases, IDD can cause cretinism and in more mild ones causes goitre.

In 1993, 370 million Chinese people lived in IDD endemic areas, which was 40% of the global at-risk population.[37] The economic cost to China is estimated to be $50bn.[38] After becoming aware of the scale of the problem, China launched the National Iodine Deficiency Disorders Elimination Program in 1993. The program made regions aware of the problem of IDD; strengthened the capacity of the salt industry to iodise; improved monitoring of the quality of salt; and banned non-iodised salt.[39] According to Goh, as a result, the rate of goitre (an illness caused by IDD) among children aged 8-10 fell from 20.4% in 1995 to 8.8% in 1999.[40] We have deduced the following cost-effectiveness estimate:

According to The Copenhagen Consensus salt iodisation was the most cost-effective and desirable intervention available to the world in 2012.[41]

The achievements of these public health interventions are enormous. They are all large-scale, national and international programs which have brought massive benefits at very low cost. The focus here has been chiefly historical, but the successes of the past may guide us towards success in the future. Humanity has done a great deal of good. The challenge we now face is to do the most good possible while we can.

Copenhagen Consensus: How much have global problems cost the world?

See William Easterly, The White Man’s Burden : Why the West’s Efforts to Aid the Rest Have Done so Much Ill and so Little Good (New York: Penguin Press, 2006); Dambisa Moyo, Dead Aid : Why Aid Is Not Working and How There Is Another Way for Africa (London: Allen Lane, 2008).

The full report provides a more thorough examination of the evidence.

To determine the number of DALYs lost due to a disease, a weight factor that reflects the severity of the disease on a scale of zero (perfect health) to one (death) is assigned to the disease. See 

Nancy Devlin and David Parkin, “Does NICE Have a Cost-Effectiveness Threshold and What Other Factors Influence Its Decisions? A Binary Choice Analysis,” Health Economics 13, no. 5 (2004): 437–52.

Give Well: a model for cost-effectiveness of interventions

Ruth Levine, Case Studies in Global Health : Millions Saved (Sudbury, Mass; London: Jones and Bartlett, 2007); Frank Fenner et al., 

 1988, 1363, . The individual case study from Millions Saved is available 

Fenner et al., “Smallpox and Its Eradication,” 1365–1366.

[here]( Levine, Case Studies in Global Health; Fenner et al., “Smallpox and Its Eradication,” 1363. The individual case study from Millions Saved is available <a href=).

Giving What We Can: Neglected Tropical Diseases

Ernesto Ruiz-Tiben and Donald R. Hopkins, “Dracunculiasis (Guinea Worm Disease) Eradication,” Advances in Parasitology 61 (2006): 280–282.

“WHO | Dracunculiasis (guinea-Worm Disease),”

“WHO | Dracunculiasis (guinea-Worm Disease).”

For an explanation of how I arrived at this figure, see the full report.

Give Well: Cost-Effectiveness of Guinea-Worm Eradication

. Givewell notes that the cost of completing eradication may be much greater.

M. EI-Rafie et al., “Effect of Diarrhoeal Disease Control on Infant and Childhood Mortality in Egypt: Report from the National Control of Diarrheal Diseases Project,” The Lancet, Originally published as Volume 1, Issue 8685, 335, no. 8685 (February 10, 1990): 334–38, doi:10.1016/0140-6736(90)90616-D.

Miller and Hirschhorn, “The Effect of a National Control of Diarrheal Diseases Program on Mortality.”

EI-Rafie et al., “Effect of Diarrhoeal Disease Control on Infant and Childhood Mortality in Egypt,” 335.

See Miller and Hirschhorn, “The Effect of a National Control of Diarrheal Diseases Program on Mortality”; EI-Rafie et al., “Effect of Diarrhoeal Disease Control on Infant and Childhood Mortality in Egypt.” The CDG case study somewhat misleadingly reports this figure at page 7 of 

 . I have been unable to get my hands on the stated source for the $43m figure. Miller and Hirschhorn say that the grant assistance totalled $32m. See Miller and Hirschhorn, “The Effect of a National Control of Diarrheal Diseases Program on Mortality.”

Eric De Jonghe et al., “Cost-Effectiveness of Chemotherapy for Sputum Smear-Positive Pulmonary Tuberculosis in Malawi, Mozambique and Tanzania,” The International Journal of Health Planning and Management 9, no. 2 (April 1, 1994): 154–155, doi:10.1002/hpm.4740090204.

“WHO | Micronutrient Deficiencies - IDD,” WHO, accessed September 17, 2014, 

http://www.who.int/nutrition/topics/idd/en/

T. Ma, J. Guo, and F. Wang, “The Epidemiology of Iodine-Deficiency Diseases in China,” The American Journal of Clinical Nutrition 57, no. 2 Suppl (February 1993): 264S.

Chor-Ching Goh, “Combating Iodine Deficiency: Lessons from China, Indonesia, and Madagascar,” Food & Nutrition Bulletin 23, no. 3 (September 1, 2002): 280–91.

“Copenhagen Consensus 2012 - Outcome”

 accessed September 17, 2014,. See the assessment paper 

Road Traffic Injuries: how effective is prevention?

Most of us have seen the aftermath of numerous road accidents and many of us will have been in one ourselves, but we are likely to underestimate the sheer scale of the devastation caused by road traffic injuries (RTIs). In 2010, according to the Global Burden of Disease Study, RTIs killed around 1.33 million people worldwide [4] – more than 

, ahead of diseases like tuberculosis [9].

Global years of life lost ranks with 95% Uncertainty Intervals for the top 25 causes in 2010 [4]

 of people killed in the wars in Iraq and Afghanistan over the last decade. In addition, between 20 and 50 million people are estimated to be disabled or injured each year.[5] 

, with 80% of road traffic deaths but only 52% of the world’s registered vehicles.[7] Perhaps surprisingly, half of all road deaths are among pedestrians, cyclists and motorcyclists.[7]

Looking to the future, as low and middle income countries develop and more people are able to afford motorised transport, 

the number of road deaths is likely to increase

. The WHO projects that road deaths will overtake HIV/AIDS and diarrheal disease as a cause of death by 2030.[9]

Attribution of fatal road traffic injuries by road user group in sub-Saharan Africa and in South East Asia [1]

The annual global economic costs of RTIs are estimated at 

, though the WHO says this figure may be a considerable underestimate.[5] Moreover, in many countries road safety efforts go underfunded.

As a consequence of the startling problem of RTIs, the UN General Assembly proclaimed a Decade of Action for Road Safety (2011-2020).[6] However, today less than 10% of the world population has comprehensive legislation on all five key risk factors for road safety: speed, drink-driving, helmets, seat belts and child restraints.[7]

Increase in the percentage of world population covered by comprehensive legislation on five key road safety risk factors 2008-2011 [7]

significant room for improvement at the policy level

 try to provide information for policymakers on which interventions produce the most human benefit for our buck. These estimates can guide us towards general areas in which there is potential for high levels of charity cost-effectiveness.

DCP2 and WHO CHOICE give very different estimates of the cost-effectiveness of road safety interventions implemented by governments. Professor Adnan Hyder, Director of The International Injury Research Unit, John Hopkins (IIRU-JH), who was involved in both the DCP2 chapter and the WHO CHOICE paper, told us that this is chiefly because they answered different questions. For WHO CHOICE the question was: what must be spent per DALY averted if there is no good legislation and no social momentum? In contrast, DCP2 asked: what must be spent per DALY averted if there is already good legislation and a supportive social environment? The results are as follows.[1, 3]

The chart below summarises the difference:

The following three interventions are assessed by only one source:

Drink driving legislation and enforcement - WHO CHOICE: $2236 in Sub-Saharan Africa and $2731 in South East Asia.

Seat belt legislation and enforcement - WHO CHOICE: $4579 in Sub-Saharan Africa and for $2502 in South East Asia.

Which estimate is most helpful for our purposes?

If the DCP2 figures can be matched by any charities, that would make them serious contenders to be amongst our recommended charities. If the WHO CHOICE estimates are more applicable, then road safety charities are much less effective than our recommended charities.

Which estimate should guide us? There are a number of factors to consider. Firstly, it is not immediately clear which of the questions by DCP2 and WHO CHOICE is more relevant for our purposes here. On the one hand, governments rather than road safety charities would bear most of the costs of sustaining the interventions over time a ten year period, but on the other, some of the areas in which the most promising road safety charities operate – South East Asia and Africa – to a large extent lack a supportive regulative and social framework.

the cost-effectiveness of road safety charities will be somewhere between the DCP2 and WHO CHOICE estimates

. A cost-effectiveness projection of a programme recently implemented by the road safety charity Bloomberg Philanthropies may be instructive. The study projects that the intervention would save a year of life for around $300, which is around a fifth as cost-effective as our recommended charities. [2]

All of this said, the most important thing to note here is that the existing data appears to be very limited. Esperato et al note that the available academic articles on cost-effectiveness exhibit four main weaknesses:

These are (1) not focusing on a specific intervention, (2) not having specific baseline data, (3) not having a control group (i.e., counterfactual), and (4) not adjusting for potential confounders.[2]

For example, only two of the effectiveness studies they found accounted for the counterfactual by having a control, and only one study accounted for potential confounders. Given that Esperato et al engaged in such a wide-ranging literature view, this should make us have serious doubts about the robustness of any existing cost-effectiveness estimates of road safety interventions in the developing world. WHO CHOICE and DCP2 also seem to be working with very limited developing world data.

In sum, we do not yet have reason to completely rule out road safety charities, but we should be suspicious about claims that they could rival our currently recommended charities. Unless a road safety charity presents strong evidence showing the high cost-effectiveness of their activities, we ought not to recommend them.

There are relatively few road safety charities and of the major ones than exist, many of them are quite young. We looked at a range of traffic charities and have concluded that 

though none should be recommended now, three may be worth assessing again in a few years’ time

The International Road Assessment Program (iRap)

iRap engages in a range of activities, including inspecting high-risk roads and developing star ratings, safer roads investment plans and risk maps. They also track road safety performance so that funding agencies can assess the benefits of their investments.

 of prospective road infrastructure projects across the world. They suggest that some government projects can avert a death or serious injury for less than $200. However, these are cost-effectiveness assessments of government projects, not of donating to iRap itself. So far as we know, they have yet to perform a cost-effectiveness assessment of their own work and they did not respond to our queries about their own cost-effectiveness. Nonetheless, there work appears to be potentially high impact. It would be worth enquiring again in a one or two years to see if they have performed any cost-effectiveness analyses of their own work.

The AIP Foundation is an Asian NGO which has a five pillar approach to road safety: programmes targeted at vulnerable road users; public awareness education; legislative advocacy; helmet production; and research monitoring and evaluation of their efforts.

AIP Foundation has various impressive achievements so far. In 2007, they combined legislative advocacy and public awareness education to successfully push for mandatory motorbike helmet laws in Vietnam. This has undoubtedly saved many lives. Nellie Moore, their Junior Monitoring & Evaluation Manager, told us that, by their own estimates, as a result of the programme, $2.6bn was saved, 412,200 road injuries were avoided and 20,600 fatalities were prevented in Vietnam. If this is accurate, then AIP Foundation is potentially very cost-effective. It spent nearly $2.5m in 2013. If we assume it spent $2m every ten years with the sole consequence of a mandatory helmet law in Vietnam which saved 20,600 lives, then their activities would have saved a life for $970. This is around half the cost offered by our recommended charities.

However, there are a number of caveats. Firstly, they have yet to do a rigorous cost-effectiveness study of their own work. Ms Moore told me they are carrying two out at present, which should both be ready by next year. Secondly, it is not clear whether the helmet legislation would have happened anyway without the efforts of AIP Foundation. Thirdly, Vietnam might have been a particularly good opportunity for motorbike helmet intervention, which could not be matched in other countries.

There is, then, reason to be cautious around claims about the cost-effectiveness of AIP Foundation, but nevertheless to be optimistic about the good it does. We recommend returning to this charity in one or two years to look at the outcomes of its cost-effectiveness assessments.

Amend operates in Africa and according to the WHO “the interventions promoted by Amend are perfectly in line” with those being promoted by the WHO.

Amend’s Director Jeffrey Witte provided helpful information when asked about cost-effectiveness. Overall, the message was that at the moment we simply do not know enough to reach a verdict about the cost-effectiveness of interventions in the developing world. He said that there are very few or zero papers which prove to a standard publishable in a peer-reviewed journal that any intervention has reduced RTIs in Africa (or anywhere else in the developing world). However, in January, Amend is to embark on a two year project funded by the FIA Foundation to perform a rigorous evaluation of the impact of their infrastructure programme on injury rates.

Amend’s scientific focus is certainly to be commended and it would be worth looking again at them in a few years’ time.

RTIs are a huge and growing problem across the world. However, what data there is at the moment suggests that it is unlikely that any road safety charity could rival our currently recommended charities. Moreover, there is very limited data on the cost-effectiveness of road safety interventions in the developing world. Some charities operating in the area are promising and we ought to return to assess them again in a few years’ time. For now however, we cannot recommend any road safety charities.

Road Traffic Injuries: Assessing The Global Burden And Charities Working In The Area (PDF)

, Giving What We Can's comprehensive report into Road Traffic Injuries

Chisholm, D., H. Naci, A. A. Hyder, N. T. Tran, and M. Peden. “Cost Effectiveness of Strategies to Combat Road Traffic Injuries in Sub-Saharan Africa and South East Asia: Mathematical Modelling Study.” BMJ 344, no. mar02 1 (March 2, 2012): e612–e612. doi:10.1136/bmj.e612.

Esperato, Alexo, David Bishai, and Adnan A. Hyder. “Projecting the Health and Economic Impact of Road Safety Initiatives: A Case Study of a Multi-Country Project.” Traffic Injury Prevention 13, no. sup1 (2012): 82–89

Jamison, Dean T., World Bank, and Disease Control Priorities Project. Disease Control Priorities in Developing Countries. 2nd ed. New York: Oxford University Press ; Washington, DC, 2006

Lozano, Rafael, Mohsen Naghavi, Kyle Foreman, Stephen Lim, Kenji Shibuya, Victor Aboyans, Jerry Abraham, et al. “Global and Regional Mortality from 235 Causes of Death for 20 Age Groups in 1990 and 2010: A Systematic Analysis for the Global Burden of Disease Study 2010.” The Lancet 380, no. 9859 (December 2012): 2095–2128. doi:10.1016/S0140-6736(12)61728-0

Peden, M., Richard Scurfield, David Sleet, Dinesh Mohan, Adnan A. Hyder, Eva Jarawan, and Colin Mathers. 

WHO | World Report on Road Traffic Injury Prevention.

WHO | Global Plan for the Decade of Action for Road Safety 2011-2020.

WHO | Global Status Report on Road Safety 2013.

WHO | Investing in Health Research and Development.

WHO | Projections of Mortality and Causes of Death, 2015 and 2030.

John holds a doctorate in political philosophy and formerly worked as a research analyst for the Global Priorities Project at the Centre for Effective Altruism.

John Halstead

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Articles

The Best Public Health Interventions of the 20th Century

Road Traffic Injuries: how effective is prevention?