Measurements of global health can be wildly inconsistent and subjective. In Epic Measures, Alan Lopez, a scholar in global and public health, described how the World Health Organization (WHO), United Nations, and World Bank’s statistics can sometimes be extremely misleading due to faulty assumptions or lack of consistency in their methods of data collection. Lopez says that in the 1970s, when the World Bank lacked information about life expectancy in any given country, it would simply assume that life expectancy would increase steadily over time and create statistics based on that assumption, which could be severely wrong. Lopez also later found a dramatic inconsistency between the UN and WHO’s figures for child death in 1980; the former had 20 million and the latter had 30 million. He realized that the WHO over-counted by 10 million because it counted deaths from different diseases separately without taking into account that sometimes children had multiple diseases that contributed to their death. And Lopez also said that WHO generally takes the statistics about death and disease provided by governments at face value without checking other sources, even when they vary significantly. These statistics aren’t as reliable as we might think.
Not only that, but as noted by global health scholar Chris Murray, global health statistics were, at that point, concerned with a far too narrow set of issues. They focused mainly on child mortality and largely ignored disability. And if disability wasn’t tracked, that meant that coming up with ways to address it would be significantly harder. Moreover, judging which health issues are most urgent is much more difficult when one lacks comprehensive information about many and a means to compare them. Murray sought to address this by coming up with a way to compare the relative severity of a wide range of health issues on a large scale: the Disability-Adjusted Life Year, or DALY (pronounced like “dally”). This measure would later be used by Murray for his Global Burden of Disease study.
The DALY is meant to quantify the impact that a disability may have on one’s quality of life in relationship to mortality. It’s a descendant of another measure used by demographers known as “potential years of life lost” (YLLs), in which anything that kills you before the average lifespan is represented by the loss of years that you’re assumed to have otherwise lived. The DALY extends this concept to disability. While conditions that result in early death would be assigned a value that represents the amount of years lost due to that death, based on an assumed lifespan in the absence of that condition. A given disability may be assigned a certain decimal value to represent an amount of healthy life lost per year, which Murray called “years lived with disability” (YLDs). For example, in his scale, deafness is given a 0.2 weighting and depression a 0.6, meaning that in a decade, deafness is equivalent to two years of healthy life lost and depression is equivalent to six years lost. In this way, DALYs enable one to compare the impact of disability with the impact of fatal conditions by making it so that both are measured by the same unit, in order to ascertain which may be most pressing.
The importance of measuring the prevalence of disabilities worldwide is clear. However, I find myself a bit troubled by some of the underlying assumptions involved in the creation of the DALY. One of Murray’s former employees at the WHO, Josh Salomon, argued that it was better for the DALY to use non-disabled people’s assessments of the severity of a disability, because disabled people tend to rate the severity of their disabilities lower than non-disabled people, and they didn’t want to “penalize” disabled people for having learned to cope with their disability. However, this assessment overlooks some important reasons why disabled people might rate their disabilities differently from those who don’t have the same disabilities. For example, autistic people often have very different opinions about autism than non-autistic people. Part of this is due to misinformation about autism that has been spread by organizations like Autism Speaks, which misrepresent autism as something horrific or worse than death. Autistic people also often object to the idea of a “cure” for autism altogether. They feel that autism is fundamental to who they are, and believe that it would be better if society instead became more understanding and accommodating of different ways of thinking, rather than seeking to erase autistic people from existence. Such nuances are lost when the opinions of disabled people are not specifically sought out. The DALY values may be skewed by misinformation among the general public about a given disability, and proposed treatments as a result may not reflect what disabled people themselves want.
The comparison between disability and lost years of life also brings troubling implications. There is an objection in wider disability activism to the idea that often arises that one would rather be dead than disabled. Disability activists see this point of view as a reflection of society’s dismissal of and disrespect for disabled people. This arises particularly in arguments against euthanasia, including that disabled people may be pressured into making this choice by doctors. Though the DALY does not make this claim or advocate for such measures, the comparison of disability to death nonetheless may reinforce counterproductive ideas about disability. And, again, the use of non-disabled people’s opinions on disability could skew results in a misleading way. While it’s important to be able to measure all kinds of health concerns, including disability, on a global scale, the researchers behind the DALY could have benefited by becoming more informed on the perspectives of disabled people themselves. The lack of emphasis on input by disabled people could, in fact, lessen its usefulness for disabled communities.