How to best measure health has been a highly debated topic over the past few decades. Perhaps the most common way of measuring health is by looking at life expectancy. The burdens of certain diseases have mainly been calculated by counting the number of deaths they cause. Where did our methods of measuring health come from? And what do we end up missing when we focus on life expectancy and counting deaths alone?
Demographers and epidemiologists, specialists in measuring health, attempt to measure health in very different ways. Demographers primarily study rates of mortality by age and sex, while epidemiologists study specific diseases- what causes them, who they affect, and how they may be controlled. These methods used alone, however, are insufficient if we want a comprehensive picture of global health. In order to measure health, we must study both who dies and what they die of. This task is accomplished by combining the work of demographers and epidemiologists into the Global Burden of Disease study.
So we want to measure who dies and what they die of-where do we even begin? Much of the data used to answer these questions comes from government officials. At the World Health Organization (WHO), governments have generally been considered the authority on health statistics in their respective countries. This becomes a problem, however, when countries incorrectly report their deaths. Sometimes this is on purpose, such as when North Korea reported absolutely no disease, and sometimes countries simply do not have the tools to garner accurate data.
Another problem with determining who dies of what is incorrectly reported cause of death. This problem became apparent when the child mortality estimates of the WHO were compared to those of the UN. The WHO reported 30 million child deaths in 1980, while the UN reported fewer than 20 million in the same year. This discrepancy seems extreme, but the cause is actually fairly apparent. The estimates of the WHO were a summation of child deaths from each disease. It is likely, therefore, that it was simply a problem of double (or even triple) counting. A child who dies of pneumonia may also have diarrhea and malaria. If this single child is counted as a death from pneumonia and a death from diarrhea and a death from malaria, one death turns into three deaths. The WHO is seen as an authority on the subject of public health, and yet their numbers were wrong.
Why would anyone be reporting incorrect data? The simple answer is money. Donors want to give money to causes that seem the most in need, therefore they are more likely to donate to causes that affect the most people. If a donor hears that 2 million children are dying of malaria, they are more likely to donate to that cause than if they hear that only 1 million children are dying of malaria. The unfortunate problem with fixing these numbers, therefore, is that donors will lose faith in the organization if their numbers change dramatically.
The IHME, in their Global Burden of Disease study, attempted to remedy the problem of incorrect data by communicating directly with the leaders of nations and experts on health in these nations. Many of the countries studied would later go on to conduct their own burden of disease studies, leading to even more accurate information on the topic of health. Through these methods, the Global Burden of Disease became one of the most accurate studies to track global health to date.
So far, the major way of measuring health has been through tracking death. When we focus only on deaths, we miss a large part of health. Diseases that don’t kill us cause much suffering and loss of health. These diseases range from low back and neck pain to depression and anxiety. For years, no one took disability into account. Then came Chris Murray and the DALY. DALY stands for Disability Adjusted Life Years, and it is a crucial part of the Burden of Disease study. In calculating a DALY, each year of life lost to early death is counted as one year lost, and years lived with disability are counted as a fraction of a year based on the severity of the disability. For example, a year of life lived with severe anemia is counted as 0.9 of a year of healthy life, and a year of life lived with major depression is counted as 0.5 of a year of healthy life because of the diminished quality of life that these conditions cause.
The DALY has the ability to revolutionize the way we measure health. For the first time, chronic conditions are taken into account, and conditions that affect a great deal of people are no longer overlooked. The burden of disease causes so much more than death alone, therefore DALYs allow us to paint a much more accurate picture of the true burden of disease.
Through the Global Burden of Disease Study and the invention of the DALY, we are now able to measure health in new and revolutionary ways. Measuring health has gone beyond counting deaths to determining what truly ails the world. Considering the amount of false information out there, however, we can never be too skeptical of global health data. Skepticism engenders change.