Arquivo diário: 12/05/2015

Lectures / Readings

Introduction to Public Health IV

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Measurin Health Status

When we talk of health we also need to measure it, because as is often being said in management circles, what gets measured gets done. So when we plan health programs, then we need to find out what the impact of those programs is in terms of improving health indicators.

This is important for national systems to look at how they’re functioning and faring in terms of various health priorities. It’s also important to compare across different countries, over time within countries and across geographies in different countries and sometimes over time in terms of the global trends.

Policymakers will also find it very important not only to use it as a measure of progress, but also for priority setting. Clearly when there are a number of priorities which need to be addressed in terms of different health challenges, and they have to allocate resources, they will have to decide which are the ones which are really the most important in terms of tackling early on and those which can be tackled later on or how to allocate resources across different programs.

The WHO defines health as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.Therefore it s a positive definition, not a negative definition, therefore it goes beyond the absence of disease or infirmity in stating positive attributes of health.

However, it s a holistic definition which is very pleasing but difficult to measure and pin down. So how do we actually measure health? One of the important measures is longevity because as societies advance one expects life expectancy to improve and life to grow longer and longer. So that depends upon when and why people die. And that captures the life expectancy on an average within a country. But as we know, there are wide disparities in life expectancy across different countries. Japan for example has a life expectancy of 83 years, whereas Mozambique has a life expectancy of 53 years and in between we have Sweden at 82, Bangladesh at 70 and Tanzania at 59.

But the important thing to remember is that while we must try and reduce this huge gap in life expectancy as a measure of health across the world, it is quite clear that all the years of life are not lived in good health. So there are some years which are compromised by ill health. And therefore we are also looking at a modified measure of life expectancy which is healthy life expectancy. That means if you remove the amount of years lost due to ill health, by adjusting in some way for the level of ill health and the years lived with ill health and then subtract that from the total life expectancy, then you come to healthy life expectancy. And Japan in this case has 75, which is very good. That means the gap between life expectancy and health life expectancy is not very large.

On the other hand, Mozambique which started off with a low life expectancy has a very low healthy life expectancy of only 37. And the gap therefore is quite substantial of 16 years. That means, even in the shortened life expectancy of Mozambique, several years

are consumed by ill health. So when we re looking at cause of death for example, one of the very important measures in international comparisons, there is an international classification of diseases which was first proposed by William Farr. And now we are in the tenth revision. So different diseases are provided different criteria of diagnosis and then we attribute the cause of death to the most important cause that contributed to death. And then we compare again, across countries as to which are the dominant contributors to death and within in countries too we compare across social groups and we compare across time periods to see whether there are transitions occurring or whether health policies and health programs have had the desired impact.

And some of these are also linked to individual causes of death or age groups or particular types of programs that we are really trying to assess. Like for example, infant mortality rate, child mortality rate, maternal mortality ratio, or disease specific mortality. What is the mortality contributed by cardiovascular diseases as a whole and what is the mortality contributed by coronary heart disease and stroke separately? So we look at all of these in a manner that is disease specific.

And this we gain from different sources of information. Usually countries should have vital registration systems which are quite robust. They should also have very good cause of death certification procedures based on the international classification of diseases. You can t go around classifying death in a very arbitrary manner and then expect good comparison. So you need a standardized method of certifying death and physicians and others who certify death must be trained properly to really adhere to that. Others include hospital records, national and international surveys like demographic health surveillance systems,sample registration systems and so on. Cause of death information is best generated from systems of civil registration and vital statistics. When these systems are either incomplete or dysfunctional and not really reliable in terms of the validity of the information generated or the completeness of information generated, we can still attempt to gain some useful information on births and deaths from other sources. These include demographic surveillance sites, sample registration systems, population censuses and household sample surveys.

None of them give the full information that we can get from civil registration systems. However by supplementing the limited information that they offer with structured verbal autopsy techniques, we ll be able to get additional information which can inform policy and programs even as civil registration systems are being established or strengthened.

In some countries where the vital registration systems and cause of death certification is not very widespread, well established, or reliable, people also undertake techniques known as verbal autopsy. In order to try and send trained people into the community to try and identify deaths which have taken placeand then through a very well structured interview, try and ascertain what the potential causes of death might have been in those cases. And these are usually verified against available medical records or a physician opinion. So there are different ways of ascertaining mortality data.

But we also need to measure morbidity because death is not the only thing that matters in life. Good health matters and therefore living a life in good health without disability is a very important objective in any society. And therefore we have to measure disability or handicap. And therefore we have to first start defining disability. So every disease carries a certain degree of disability. In some cases, very short-lived, in some cases chronic or in some cases, permanent. So we have to try and measure what the durational disability is and what the degree disability is. So in terms of health expectancy measures, we do look at disability measures and there are multiple disability measures that are there for different categories of diseases. But again, we are faced with a challenge of compressing all of this into one or two indicators which capture all of the information. And there we ideally should look for measures that combine mortality and morbidity, particularly for comparisons across countries and comparisons over time within countries.

So disability adjusted life expectancy has been something that was proposed in the World Health report of year 2000. And now it s called Healthy Life Expectancy. If you assess the nature of disability, attach some weights to it, estimate the number of years lived with that particular disability which could vary actually in terms of its severity across those years, but ultimately calculate the cumulative loss of healthy life years because of the disability and subtract that from the overall life expectancy, then you get healthy life expectancy. So this measures the equivalent number of years expected to be lived in full health.

Now there is another measure that has come in to play, particularly through the global burden of disease project. This was first introduced into global health in the year 1994. This was again to capture the combined burden imposed by premature mortality and prolonged disability as a summative measure. It combines the years of life lost due to premature death and the years lived with disability weighted for the degree of disability. And therefore it subtracts the amount of life lost because of that weighted disability. And this again has become an important measure though it has become a little controversial sometimes by saying that it s a bit of an ageist measure and then it sets too much premium on years of life lost and substantially overweighs certain categories of death and disease over others. But nevertheless it s a useful measure for global comparison.

At the same time, there are other estimates that have come in in terms of measuring health gaps. Years of life lost. This is estimated on a population basis, compared to potential maximum life expectancy, which in this case is Japan. Then we also look at years lived with disability. These are all subcomponent measures of the DALYs. These all go into the calculation of disability adjusted life year lost. So the years lived with disability, they estimated on a population basis the number of cases with that particular condition must be multiplied by the average duration of the disease and a weight factor that reflects the severity of the disease on a scale from zero, which is perfect health to one which is death.

The global burden of disease studies as I said, first started in 1990. They were published in the first version in 1994 and subsequently they have been revised extensively in 2010 and are going to be also periodically revised. And currently the Institute for Health Metrics and Evaluation in the University of Washington-Seattle is now leading this effort. And they do comparisons of global burden of disease across different countries and groups of countries using the disability adjusted life years. This has had an unprecedented scale and effort going into this, of looking at multiple data sources and compressing that all into a measure that provides for global comparison. It does give a global picture of progress and the status of health which is not available presently through any other source because most of the other measures fall short either in terms of measurement of disability or being very disease specific or particular age specific.

But it also is an important measure for highlighting emerging focus areas and improvements in health. For example, in 1994, when the first global burden of disease study came in, people were surprised to note that many of the low and middle income countries already had very advanced epidemics of non-communicable diseases where there was a lot of premature mortality and a lot of disability. And until the calculations of disability adjusted life year loss was done, mental health did not emerge as a very major factor in global health. So the DALYs calculated for all of these were a great contribution in helping us to re-prioritize some of our public health interventions.

But there are some justifiable criticisms. There are always issues raised on the quality of data available from different countries and ultimately whatever is the summative measure is dependent upon the quality of the data and the extrapolations made. And again, there is a little criticism that this is an ageist measure and this weighting system also is sometimes controversial. The amount of weights attached by patients, by physicians and by people who are healthy tend to vary. And therefore we re not sure which the actual weight to be utilized is. The DALYs and the global burden of disease are supposed to be guides to resource allocation, but they do not always account for differentials in resource availability.

Remember, sometimes you have to take equity also into consideration. You have to take affordability issues into consideration. And there are multiple other factors that go into policymaking. Nevertheless, for prioritizing public health action and to some extent resource allocation, the GBD is useful indeed. We understand that measuring disease burdens is a complex activity but a very important activity. It s an evolving process. We are still gathering knowledge about what are the best methods of assessing disease and the disease burdens and measuring health free from disease but global health requires these metrics for decision-making, for comparison and for advancing our progress to adequately prioritized public health programs.

But we also recognize that health now must be positioned fairly effectively in the broader developmental context. It can t be seen in isolation from other developmental activities, including the whole area of sustainable development which is now coming to the fore in the United Nations. So there are some of the indices that are coming up in which health forms a part of a broader development index. Dissatisfied with the gross domestic product as an indicator of economic progress, Stiglitz, Sen and Fitoussi who are very major international economists developed what is known as a well-being index which captures multiple areas including environment, education, poverty reduction, health, among several others. And therefore this is a composite index. There is a multidimensional poverty index developed at Oxford which looks at health, education and living standards and measures poverty in multiple dimensions, including the lack of health. There is a social progress index that s currently under development which looks at basic human needs, foundations of well-being, opportunity and brings in some of the environmental concerns as well.

So as we move towards the sustainable development goals we need to definitely improve our measures of health, but we also need to see how we can coalesce those measures with other developmental indicators to get an idea of what a healthy society should be in all dimensions.

Lectures / Readings

Introduction to Public Health III

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Evolution of Global Public Health

We have seen that concepts of public health are centuries old. However the idea of global public health has been evolving over the last few decades. And this has been brought about by substantial changes in the way people have looked at international health and then, and global health. Peter Piot, who is the director of the London School of Hygiene and Tropical Medicine and previously the director general of the UNAIDS has classified global public health in four stages. The first stage was one of tropical medicine. This was during the colonial period when many of the countries which colonized countries in Africa, Asia or Latin America were concerned about their soldiers and their traders as well as their administrators suffering from the tropical diseases like malaria. And they invested in programs for prevention and control primarily to protect their own people and their commercial interests and of course the local population benefited incidentally.

But then we moved on to an era of international health in the post-colonial period in which people were interested in finding out what the health trends in different countries were and what the comparative profile of public health challenges and predominant diseases was in the world. Indeed, this is not a curiosity that is very recent. Even in the 19th Century, epidemiology was principally described as geographical epidemiology. And therefore the whole idea of geographical medicine in which they compared people across different countries. But we now see that apart from international health, we have moved on to a third stage where people from rich countries who are leading research programs in poor countries started organizing substantial research programs funded often by the governments or donor agencies from rich countries in order to investigate the causes and course of diseases in the poor countries, more as a matter of international cooperation. But now global public health have entered a fourth stage. Where global health activities, including research are being led by people from poor countries. Indeed, there’s a much greater amount of collaboration including leadership of major programs by researchers as well as public health leaders from the low and middle income countries. I would actually put it in a slightly different way. I would say international health was when people went from the high income countries to low income countries and said, what can we do for you? And now global health is where people everywhere in the world are sitting across the table together and saying, what can we do together to identify and solve the leading health problems of the world by working together? I think the recognition that many of the determinants of health today are transnational, whether it is movement of viruses or migration of people or sale of tobacco and essential medicines, all of these have become transnational activities. So global cooperation is absolutely critical now if people have to solve the problems of global health. And it is this working together that really brings life to global health in the 21st Century. The whole idea is that we are really looking at not merely variations in health across the  world, but we are looking at common concerns and commitments in global health.

The 20th Century saw global health advancing primarily from a sense of shared vulnerability. There was this threat of bioterrorism. There was the big scare about SARS, H1N1. And many avian influenzas and so on. And people felt that they needed to protect themselves against various diseases that were moving across boundaries. The International Health Regulations came in. And of course we started looking at cooperation merely from the point of view of protecting ourselves against problems that can come in from elsewhere in the world. But in the 21st Century, we are moving beyond shared vulnerability to shared values to provide momentum to global health, because we are looking at issues like universal health coverage. We are looking at trying to reduce inequities across the world. We are looking at sharing knowledge and resources for improving health of people everywhere across the world, whether it is battling under-nutrition or whether it is battling Ebola.

And therefore we ought to be really looking at the fundamental values that guide global health in the 21st Century and that is universality. But universality doesn’t mean that everything is decided at the global level. We do have decisions to be made at the local level and a lot of action is led at the country level or even at the sub regional level within countries. As the Portuguese writer, Miguel Torga said, universal is local without walls. What we have done is to break down the walls in terms of shared knowledge and built bridges of cooperation across the world to tackle the problems, even as we are acting both at local and the global levels. Now what are we studying in global health nowadays? We are looking at trends in demographic transitions across the world where we’re trying to find out how aging populations are now facing different disease burdens. We are looking at the changing nature of disease burdens both in response to demographic as well as economic transitions. And we are looking at how risk factor levels are rising or falling across populations to predict what the disease patterns are going to be. We are also studying the broader social determinants of health, because they are fundamental to determining the health of populations. We are also looking at how the national health systems are responding to the various public health challenges. What are the allocation of financial resources for health within countries? For example, if you’re really looking at universal health coverage, can it be funded at a low level of resources or do the resources need to be augmented? We are looking at health workforce issues. Do we have a multilayered, multi-skilled health workforce, which is capable of delivering a wide range of services which are promised in universal health coverage? We are looking at the access to drugs, vaccines and technologies and trying to find out whether countries need to be supported in promoting greater access and affordability for their populations. We are looking at how health systems are organized. Are there vertical disease programs or is there horizontal integration or what we are now calling a diagonal approach in which there is a certain degree of focus and verticality within a health program but the results are a great amount of sharing and capacity-building for the health system which can be accommodated even within a vertical program which can also support some other objectives of some of the allied programs.

So we are looking at rapidly evolving models of health systems. We are also looking atpublic health emergencies whether it is Ebola or natural disasters and seeing how health systems in general are capable of responding to it, how they’re collaborating with othernational disaster response systems and how international cooperation can help in that. So if somebody is really suffering as a result of Ebola in Africa or somebody is suffering as a result of a post-tsunami effect in Indonesia, it does not mean that they’re going to be isolated. There’s a whole global health community which is going to be responding to that challenge. And that is the essence of global health.

So we are also looking at global health constructs. We are looking at flows of knowledge, technology and services across the world. We are looking at reverse innovation. We have had Lord Nigel Crisp from the United Kingdom who headed the British National Health Service. He was sent by Prime Minister Tony Blair to look at countries in Africa, Asia and Latin America to see what the National Health Service could provide those health systems in terms of support and guidance, in terms of sharing best practices. He came back after a good study and wrote a book called Turning The World Upside Down. He said, there are so many innovations going on in these countries of Africa, Asia, and Latin America, which the British National Health Service could benefit from. So he said, the whole world is now a very different place.

You’re seeing a lot of innovation happening in the so-called low and middle income countries which the high income countries should learn about. So there is a greater opportunity for bidirectional, or multidirectional sharing of knowledge. And of course, we require much greater cooperation as well in terms of not only scientific research, but also in the application of research and sharing of resources. We also are looking at governance. Not only of governance in national health systems, but how international health agencies are now trying to look at global health governance with multiple players coming in now, not only the World Health Organization, but also various foundations and a number of governments coming in, how do we coordinate the functioning of all of these agencies at the global level in order to optimize the benefits of their working together and really achieve the maximum impact on global health? So the whole idea of global health governance or governance for global health is becoming a very important area.

So also the whole area of financing of health, particularly in terms of achieving the objectives of the millennium development goals and the sustainable development goals. We are looking at transnational determinants like trade. Trade- whether it’s in tobacco, whether it is in fruit and vegetables, or in essential drugs, all of these affect health. We are looking at traffic and migration of people across continents. We are looking at conflicts which are also having refugees moving across different countries, across borders and carrying health problems with them. Or suffering their health consequences of forced migration. So we are looking at communication, how that�s bridging a lot of the knowledge gaps across the world but sometimes also creating problems by breeding unhealthy living habits as aspirational goals in changing cultures. And as we move towards the sustainable development goals from the millennium development goals We still have a problem of tuberculosis, especially multi-drug resistant tuberculosis. We still have HIVAIDS in many parts of the world. And we have now emerging infectious diseases, including zoonotic diseases like Ebola.

We are also looking at the major new challenge of non-communicable diseases. The idea of controlling cardiovascular diseases, diabetes, cancers and chronic respiratory diseases across the world becomes a major priority for global health. And we say we now move to adding NCD agenda to SDG agenda. At the same time, mental health is a major cause of disability and therefore we are looking at an expanded NCD agenda by incorporating mental health and also adding injuries in what is now being called chronic conditions and injuries agenda.

So we are looking at the prime causes of death and disability across the world and trying to accommodate all of them in the SDG agenda and global health is going to be the principle platform where this action is going to take place.

We are also looking at health equity and particularly universal health coverage. Provision of multiple services to all the people who require them, but with adequate financial protection. That has become a rallying cry for global health equity over the last 15 years. And we are going to see that resonate in the SDG goals. At the same time we are now bringing back primary healthcare very front and central into the health agenda. Alma-Ata is not dead.

We are now bringing back Alma-Ata’s spirit into SDGs by saying that universal health coverage, if it has to be delivered, has to revitalize primary healthcare. So that again is a major global health agenda. But at the same time, we have seen a fundamental shift in the way the world has looked at the health system. Previously health system was being dismissed as a black box. They were looking at vertical programs. Let’s go and attack TB. Let’s go and attack HIVAIDS. Let’s go and attack tobacco separately, and the cancer separately, and so on. Now people have realized that vertical programs, however well designed and well-intended cannot be force-fitted into a weak health system. A weak health system will not be able to deliver them. And also there is an opportunity cost of other programs suffering. So the idea of creating a strong health system which acts as a switchboard to integrate all of these programs and effectively synergize them for better delivery, including health equity that has become a primary goal of universal  health coverage and that is the driving spirit again behind global health initiatives.

So when we’re really looking at public health research which has to inform public health action, the objectives for public health research are to provide evidence based, context specific, resource sensitive, culturally compatible and equity promoting recommendations for policy and practice. And these are going to be fundamental for global health.

So when we are really looking at these as the primary objectives for driving policy and practice, we must recognize that policy whether made at national or global level has to be informed by interdisciplinary effort to create the required knowledge base. So public policy sometimes can be an unedifying spectacle when it is based on unenlightened approach. But on the other hand, even an enlightened policy needs scientific credibility. Is there evidence and rationale? For that you require biomedical and epidemiological research.

Financial feasibility. For that you need health economics research to find out whether something is cost effective or affordable for a national health budget. You require operational stability. Is the proposed intervention sustainable and scalable apart from being successful in a pilot? For that you need health systems research. But you also need political viability. Is there a ready and receptive community for accepting whatever is the proposed intervention? This could be the community of policymakers, this could be the wider community at large. And for this you need social sciences research. So unless you combine all of these fields of knowledge, you not be able to create the impetus for public health action within a country or of the global level. That’s why we emphasize bringing together multiple disciplines in order to inform and to actually guide public health action. In terms of public health practice we are really looking at integrating evidence with practices into primary healthcare for preventing and reducing the risk of diseases in a period of health transition. And ultimately when we’re acting at the level of the communities or at the level of populations, we will impact upon people and their health on…and the health of individuals.

But how do we implement all of these interventions? Now global health is beginning to talk about operational research or implementation science as a very critical piece. Previously we were trying to create knowledge about what is wrong and what could be done to set it right. But we still have not understood fully the science of delivery, especially a lot that goes into it in terms of human behavior, in terms of organizational behavior, in terms of management practices, in terms of cost effectiveness of interventions. So for all of these we require operational research or implementation science. And one of the prime elements of global health in the 21st Century is going to be implementation science.

So when we’re really talking about global health in the 21st Century, the spectrum of research must stretch from molecules to markets. The span of policy must range from persons to people to populations. And the arena of advocacy and action must extend from risk factors to rights, rights of people, human rights.

Lectures / Readings

Introduction to Public Health II

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Multiple Determinants of Health

In this chapter we’ll be looking at the determinants of health, especially the social, ecological and political determinants. Of course biology is absolutely critical too, but that is most often dealt by clinical medicine. But we will also look at the interplay of these other determinants with human biology and ultimately how they shape health at the level of populations.

Let me start with the story of Rudolf Virchow, who was an eminent pathologist in 19th Century Germany. He was also the founder of the Anthropological Society of Germany. And he had a place in the Kaiser’s court. A highly respected academic. When he was sent off by Kaiser, or the emperor of Germany to investigate an outbreak of typhus in Silesia in Prussia. He came back with a report not looking at the biology of the disease, but on the social circumstances which caused the outbreak. He said the principle cause of that outbreak of typhus in Upper Silesia was poverty and inequity. And he recommended that there should be measures taken to reduce poverty including abolition of feudal privileges and greater levels of democracy. That did not make him popular in the court, but as a philosopher of social medicine Rudolf Virchow has a very prominent place. He said, do we not always find that diseases of the populace traceable to defects in society? If disease is an expression of individual life under unfavorable circumstances, then epidemics must be indicative of mass disturbances.

He went on to say that these mass disturbances are disturbances of culture and therefore great social changes sometimes also bring epidemics in their wake. What was true of typhus in the 19th Century is true of tobacco in the 20th Century and now we are seeing other social movements which are also resulting in the epidemic of overweight and obesity because of unhealthy foods. Even in Victorian London, poor living conditions were recognized to be responsible for ill health. The Black Death of 1655 was again, strongly related to poverty and poor living conditions. And when we had epidemics in London or the United Kingdom, then the rich left the town for their estates while the poor who were to remain, suffered. And we have seen the descriptions of this kind poverty and deprivation affecting health in the books of Charles Dickens. When we look at how sometimes social circumstances can actually change for the better and thereby bring about improvements in public health, we also see the decline of tuberculosis antedated the discovery of drugs against the tubercular bacterium, or the bacillus tuberculosis. And that is where McKeown brought about his famous thesis that it is the social conditions which actually are responsible for decline in infectious diseases in countries which are improving economically.

While it is true that science and technology are also very important allies in bringing about public health improvements, we definitely have to acknowledge the important role of socioeconomic development. But this development also has to be equitable. Now we recognize that if you actually look at populations and compare them. We also find out that some of the diseases which appear to be very common in some countries are far less common in other countries, even at the same level of economic development. For example, in Finland, in the 1960s and ’70s, coronary heart disease was extremely common. Whereas at the same time in Japan, coronary heart disease was very rare. And we find that the way the populations live in terms of their living habits, of diet, physical activity, all of them are responsible considerably for these inter-population differences.

Geoffrey Rose from the United Kingdom, a famous epidemiologist, while studying cardiovascular diseases across different countries said, sick individuals come from sick populations.

If your average cholesterol level in the population is high, the number of people who will get heart attacks because of high cholesterol is going to be high. Similarly if your average blood pressure in the population is high, the number of people with hypertension who are going to get a stroke is high. So we have to really alter the population dynamics of risk acquisition and risk reduction if you want to make an impact in public health across the population. Now we also know that migration into urban environments also accounts for a great deal of this change. When you look at Kenyan nomads who live in very rural conditions and London civil servants at the same time, this is one of the earlier studies of Geoffrey Rose, you find a marked change in the distribution of the systolic blood pressure across these two populations. In London, the entire distribution is far to the right. That means even the average blood pressure as well as the proportion of those with hypertension is far higher than those in the Kenyan nomads. And therefore the way in which we lead our lives makes a difference.

This doesn’t mean that everybody has to live in relatively primitive conditions and shun modernity, but we are to make sure that as we advance towards modernity we retain some of our healthy living habits. And that is the basis of public health. So when we look at the principles of risk and prevention we understand that since much of this is determined by the population profile of a risk factor, small reductions in risk factor levels when achieved across the whole population. That means when the whole population distribution shifts to the left, shifts to a better level, then that results in a large reduction of adverse events like strokes and heart attacks across the population. Even though the individual shifts are small, cumulatively the population benefits are large. At the same time you have to also look at people who are at the high risk end of the distribution and who at the individual level have a very high risk and we have to focus public health interventions to get them the appropriate mode of risk reduction therapies. So we need to combine both of these strategies.

These are not mutually exclusive but are synergistically complimentary. But when we look at what makes people healthy, or unhealthy, we realize that there are elements in the health system which are very important. The health workforce, are there enough doctors, nurses, allied health professionals? The infrastructure, are there well equipped health facilities? Do they have enough drugs, vaccines and technologies available and affordable across the population? How is health being financed? And what are the health information systems like? Do we get ready information on what the risk factor levels in the population are? Or what is the spread of disease across the population? How is the whole system being governed? Is it efficient? Is it suffering from corruption? Is it accountable to people? All of these matter in the health system. But over and beyond that, we also have to look at the social determinants of health and nutrition. For example, these are factors operating at the societal level. Like the availability of clean water, sanitation, food systems and agricultural systems which provide healthy nutrition across the life course to every individual. A clean environment, having as little air pollution as possible. Social stability, free from conflict and violence and having adequate degree of community participation.

Then all of these matter very much in terms of the societal forces. The level of development and distribution of incomes within society matters. At the personal level, income, education, occupation, social status, gender, participation in social networks, all of these are important social determinants of health. So when we really look at all of these, public health operates at each of these levels. But underlying all of these are political and economic systems which ultimately make choices with respect to many of these determinants. We recognize for example that as per capita income grows across countries, up to a certain level the life expectancy also increases.

Once you reach a certain level of about close to ,or beyond $3000 or $4000 per capita, then the effect starts plateauing off. And this is known as the Millennium Preston Curve. But the fact is, per capita income which means the overall income as assessed as the income per population, per unit, actually matters a lot in terms of life expectancy.

However, how this is distributed within the population also matters a lot. Like for example, in the United Kingdom, there’s a huge difference in life expectancy between one county of the United Kingdom and the other county of the United Kingdom. Almost, whereas one county has a life expectancy of 54 years, the other county has a life expectancy of 82 years. Again, even within the U.S. you have differences in life expectancy which is considerable between different counties. Where in Washington you have a predominantly black population, you have 63 years as their life expectancy. On the other hand, in Montgomery County, which has a predominantly white population, you have a life expectancy of 80 years.

Now we also know that because of income differences, but also because of educational differences and employment differences you can have substantial differences in mortality rates. For example, if you look at the mortality rates across different classes of occupation, the people who are in higher grades of employment in the Whitehall which is the secretariat in the United Kingdom, they have had much lower levels of mortality as compared to some of those in the lower professional grades who, where the stress levels are much higher. And in terms of health inequalities we also recognize that educational levels play a great role.

Even at the same levels of income, differences in education make a lot of difference. Those who have had university education have a much lower mortality as compared to those with only elementary education. So there is a growing recognition that whether, between countries or within countries, we ought to be addressing inequality much more effectively. Michael Marmot who headed the WHO Commission on Social Determinants of Health remarked that the fact that there is a spread of life expectancy of 48 years among countries and a spread of 20 years or more within countries is not inevitable. This is not something that is a given, irreversible. We can, by addressing through appropriate public health strategies and equitable socioeconomic development and distribution bring about a shrinkage of these huge gaps that lie within life expectancy across and within populations. And we see this can happen in different countries where the differences between the wealth quintiles can be substantial even in terms of the number of births that are attended by skilled birth attendants. And within countries we find that the poorest, again, have unattended births with a likelihood of higher maternal mortality. But as universal health coverage takes place across countries, even in countries with lower incomes, we find that these differences across wealth quintiles are substantially reduced or even obliterated. So we ought to be really looking at universal health coverage to reduce health inequalities brought about by income inequalities. We also recognize that by making determined efforts to bring about greater equality in society you can overcome many of the existing inequalities. Brazil is a remarkable success story in this direction. After the revolution in Brazil where the military dictatorship was overthrown, and a constitution enshrining the right to health was adopted, Brazil had a number of social initiatives which were directed against reducing income inequality and reducing poverty. And that has had its effect on health. If you look at the stunting rates across income quintiles, then we find that earlier on we had a huge gap pre-revolution in the stunting rates between the high income groups and the low income groups. But subsequently we find that in the last decade these differences have greatly narrowed and we find the stunting rates in the lower and the high income groups are virtually very similar. So by bringing about a greater degree of equality in distribution and greater access to nutrition, also other social determinants of health as well as health services we can actually reduce some of the gaping health inequalities that are a major problem in terms of inequitable development. And that is a very important mandate for global health. How best can we reduce inequalities in health across populations and within populations? We do have the knowledge, we just have to apply it political will and determination supplemented by professional skill brought about by good public health systems.

Lectures / Readings

Introduction to Public Health I

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Introduction & History of Public Health

Welcome to this course on global public health. Quite often we are asked what is public health? How is it different from clinical medicine? Is it something to do with water and sanitation or is it something more? And for even people who have studied a bit of public health, they say, how is it different from epidemiology, which understands the causes of disease and identifies the means to prevent it. Others wonder what is global public health? How is it different from international health or public health in general? So let us start examining some of these questions. Firstly, public health looks at the determinants of health which act at the level of populations, or people has a whole in a community or a country, and then tries to influence those determinants so that ultimately the impact is on improving the health of individuals who constitute that community or that population.

So it doesn’t deal with the individual disease in terms of trying to identify what a person’s clinical complaint is or by providing treatment that one individual as clinical medicine does. On the other hand it tries to set right some of these determinants at the societal level so that people don’t get ill. It also tries to create robust health systems which will deliver health services in a manner that is effective as well as equitable so that people can get protected against diseases through preventive services as well as get a wider range of diagnostic, curative, palliative and rehabilitative services as needed through a well-functioning health system. And all of these also have to be done cost effectively in a manner that the health system doesn’t become bankrupt and individuals have to be protected against health related impoverishment. One of the main driving values of public health is not only to improve the health of people within communities and populations, but also to insure that there is greater degree of equity. Because even in countries where the health standards are considered to be generally very good, we see several population subgroups who do not enjoy the same good health. And we find wide disparities in life expectancy, in maternal mortality or infant mortality or even cardiovascular mortality, between these groups. So public health also aims to reduce those gaps and bridge the inequities. And when we apply the standard of equity across the world, public health then becomes global health and it also starts to examine the determinants which actually act across the global level, across countries in a transnational manner and also tries to provide a concerted multinational or a concerted worldwide response so that these determinants can be further modified to improve global health.

Now if you look at clinical medicine and take the example of somebody who died of a heart attack, well the clinician, the cardiologist would say that the person died because of blockages in the blood vessels to the heart. Absolutely true. But then the epidemiologist would say, the person developed those blockages because he had consumed tobacco as a cigarette smoker from the age of 16 and therefore he had a premature heart attack at the age of 42 and died suddenly. And therefore the cause of death according to the epidemiologist is smoking tobacco. But then the social scientist would say that in virtually every country of the world, now tobacco consumption is much more among the poor. And this poor person had consumed tobacco because he fell, trapped into the habit, did not have adequate information about it. And after having developed some other cardiac problem, did not have the ability to seek affordable healthcare and therefore died of it.

Therefore the social scientists would write down the cause of death as poverty. Now every one of them is correct. And therefore public health has to look at not only the immediate cause but the combination of causes and the causes of causes. And that is where public health becomes a very broad, integrative discipline which makes the understanding of health and disease much more holistic than any single branch of medicine.

Now in terms of public health, we also have to look at systems as I said, are doctors and nurses available in adequate numbers? Are for example affordable medicines available, accessible? Let us take for example a person who meets a nurse or a doctor in a clinic.

That is clinical medicine, if the blood pressure is being checked up and some drugs are being prescribed. But what happened to the person before he came to the clinical facility? Could the problem have been prevented by appropriate advice on how to protect health to the community? Could it have been detected early, before it went into the stage of established disease or complications? Could the referral system have functioned better by providing a timely referral? All of these issues are part of public health.

When the person leaves the clinic or the healthcare facility, are the drugs that have been prescribed by the doctor, are they available in the market? Are they affordable? Can they be taken on a long-term basis? Are the kind of dietary prescriptions given in terms of fruit and vegetables? Are they affordable again in the market? Or if it’s an infectious disease, are there systems for isolation? Are there rehabilitation support systems available for a person with mental illness, or with any other form of physical disability? All of these come under public health. Even what happens in the healthcare facility is also public health because we have to find out firstly, was there a doctor, was there a nurse? Were they adequately trained? Were they following standard management guidelines?

So the whole system organization is also part of public health. So if you want even clinical medicine to function well, you need a very strong public health system. And when you take it on the global scale and look at the determinants of disease and health on the global scale, and look at systems functioning on the global scale, including the production, export, import, regulation of drugs for example, all of that is part of global public health. So public health really covers health systems, services, policies and other sectors too.

For example, when we look at what happens in terms of agriculture, food systems and the effect on nutrition, that again has to be aligned to the health of the people. Now you may say, why do we actually think that public health links to every single system, whether it’s urban design, urban transport, agriculture? Now is there no limiting factor for this? Then we have to really understand that is the primary intent of any measure is to protect health, then that is public health. Like for example, if we say, a seatbelt law, or a motorcycle helmet law, that is public health because the primary objective is toprotect health. If the primary measure is for some other objective, but still we need to align those policies and programs and those sectors to the objectives of health, then that is not strictly in the domain of public health, but public health needs to link up with it. The primary objective of agriculture may be to provide food security, may be to provide cash for the farmers, but even there we have to insure that agriculture and food systems are producing the kind of products that are better suited to human health. So that becomes an extension of public health into another sector. So public health is truly multidisciplinary in very many ways. Now when you look at how public health has evolved this is not a new concept. Even in the Roman times there was a diversion of human waste and the Roman civilization knew that if human waste accumulated, that would be a cause of disease. That was a good public health measure.

In the 19th Century Europe we saw the so-called miasma theory coming in where they felt that miasma was bad air caused by rotting organic matter and they attributed all kinds of diseases to miasma. We know that’s not entirely true, but we also know that it is important to have clean water and good sanitation and the beginnings of the sanitary movement in Europe actually brought about marked advancement in the health of the population and that was good public health. We also know that public health can use several technologies. For example, vaccination.

Vaccination again is applied at the population level so that individuals do not get the disease. Like for example, Jenner’s vaccine in 1796, Edward Jenner brought in the vaccine against small pox. Though it is said that the Chinese used this form of variola inoculation as early as a 1000 b.c., but anyway modern documented history attributes it to Jenner. In 1747, James Lind, an English sailing captain experimented and then proved that serving lime to sailors prevented scurvy, otherwise which was a major problem on long sea voyages. And that is why the English came to be known as limeys in slang.

The history of modern public health in London began with an act of vandalism. Yes. Somebody actually broke the handle of a water pump and carried it away. And this was John Snow.

In the Broad Street in London, where there was an outbreak of cholera, where cholera was spreading across in concentric circles and affecting a large number of people, John Snow mapped out how the outbreak was spreading. And then found that the center of the circle was a pump which was actually resulting in bad water coming out because of contamination with sewage. So John Snow broke the handle of the pump and the outbreak ceased. So it’s an important measure of public health to link sanitation and good water quality to people’s health. We have had several public health movements across the world, but at the level of global health, the World Health Organization which was established in 1948 became the principle catalyst and custodian of global health movements across the world, legitimized by the will of all nations.

And one of the success stories led by the World Health Organization in terms of public health has been the eradication of small pox. We know that this very deadly infectious disease have claimed a large number of lives and even in the beginning when people started getting inoculated, there were many people who did not believe in its effectiveness, but it was very clearly shown that those who were inoculated had very little mortality whereas those who were un-inoculated had a very high fatality. And the global eradication of small pox is one of the grandest success stories of public health.

But we have also seen public health evolving in terms of the understanding of the links between health and development. In the World Health Assembly of 1977, there was a resolution of health for all which resulted ultimately in the Alma-Ata declaration which also emphasized the importance of primary health services. Then it was decided that in the whole area of environmental sustainability health also needed to be accommodated and that came about in the Brundtland Commission of 1987. But the question was whether health would automatically benefit from economic development or investments in health also were needed for accelerated economic development. And that conversation began in terms of this bidirectional relationship in the World Development Report of 1993, investing in health. It was advanced then by the Commission of Microeconomics and Health which was formed by the World Health Organization. And recognizing that health and development are integrally related, at least three direct health related goals were accommodated in the Millennium Development Goals of 2000 which were adopted by the United Nations.

And now as we move towards 2015, when the United Nations is looking at adoption of sustainable development goals, the whole relationship of public health and global public health in to sustainable development is so abundantly clear that we see global health as one of the important points around which the SDG’s will revolve. We will find they’re in one way or the other linked to global public health objectives.