You enter the emergency room or are in recovery after a surgery. A nurse walks in and says, “On a scale of one to ten, please rate your pain.” You’re giving her a measurement, a data point as to how badly your broken arm/appendix removal/knee replacement hurts right now. You’re saying, “This is how badly this problem is affecting me,” and hoping that, once you do, you’ll receive some help for the pain. If you’re a ten, your pain is urgent, and there’s probably going to be some pretty strong painkillers involved in your treatment. If you’re a two and basically have a headache, that might warrant some aspirin. Patients in more pain will also probably get more visits from the treatment team than those with less reported pain.
This is similar to how a DALY works. DALY (rhymes with Sally) stands for disability adjusted life years. Basically, it measures how much various illnesses and medical conditions affect a persons life. First, you start with average life expectancy. Then you subtract from that the age at which a person actually dies. You also subtract for years a person spent dealing with an illness or disability. This isn’t necessarily the number of years a person spent with said illness, but it is a number based on a formula that assigns a severity weight to each medical condition. Essentially, it’s a way to show the years a person lives without dealing with an illness or disability (or being dead), based on the average lifespan. A DALY shows us what effect an illness has on individual people and on the whole population. It’s a pain scale for the world to show us where and how much it hurts.
Now, that pain scale they give you in the hospital isn’t perfect. It can be a very difficult thing for people to determine for themselves, and it isn’t universal. One person’s eight could be another person’s three. Someone could overstate their pain because they want stronger medicine, or understate it to be allowed to leave sooner or receive less attention.
Language and cultural barriers could become a problem too. If something were to get lost in translation about what the numbers mean, a person could over or under rate their pain. It may be` part of a persons culture to not show or express pain. And, even once the number is given, there can still be bias in how pain is treated. Your race and/or gender can have an affect on how your pain is treated.
The pain scale is an important tool, to be clear. It allows medical professionals to get a general idea of how their patient is feeling quickly, which is important in busy and fast paced hospital environments. When information needs to be gathered and decisions need to be made quickly, having a simple pain scale can be very helpful. That doesn’t mean it should be the be-all end-all of pain measurement.
Many of these problems also come up when discussing DALYs. In creating the formula itself, determining the severity weight can be a very subjective thing. One person with an illness may say their illness effects them to a very high degree, while another with the same illness may only see it as affecting them a little. While in Jeremy Smith states in Epic Measures that the process of creating the severity weights involved many groups reaching consensus, I have to wonder who made up those groups. It says professionals and the general public, but doesn’t give much other detail. I wonder how many of those people actually experienced the illness being weighted.
There is also the problem of culture. Some cultures may have diseases that have no translation in a different language, or diseases may be viewed differently. For example, various mental illnesses in English do not have translations into another language, and the equivalent ailments may be understood very differently than their Western counterparts.
So yes, DALYs, like a pain scale, can tell you how much something “hurts”, but they also have their limitations. They are important measures, especially when major decisions have to be made on where money should go and how much attention should be paid to an issue, given limited resources. They must, however, be looked at in context, and understood as imperfect.