What is rare in medical statistics?
In Europe, a disease is rare if it affects less than 1 in every 2000 people. Let’s put that into the perspective of Ireland.
- The population of Ireland is 4,937,786 people.
- Approximately 1.4% of the Irish population have HS.
- 1.4% of that is 69,129 people
- That is approximately 28 people in every 2000 have HS in Ireland.
So, you see, HS is not rare at all.
Who Takes Part in Research?
In research, a sample is a group of people who take part in a study. Researchers figure out how many people represent the population and those are the people who take part in a study.
In a study of medical conditions, a population are those who have a particular condition, like HS. A sample is the amount of those people you need to take part in the study. If you have too few in the sample, you might miss different factors that affect different people. In medicine, there are two kinds of sample, a community sample and a clinical sample.
A community sample might be the number of people in an area who have a condition. For example, the number of people who live with HS in Ireland. A clinical sample, on the other hand, is the number of people who are in treatment for HS. HS was considered rare because community samples weren’t tested. In other words, only clinical samples took part in the studies.
The 1.4% we used to calculate the rate in Ireland is an example of a clinical sample. A 2018 study found that 1.4% of people attending dermatology clinics in Ireland where doing so for HS. It’s important to remember that 1.4% is an estimate as not everyone in Ireland who has HS attends dermatology clinics. Nevertheless, these statistics give us an idea, if not the full picture.
At this point you may be asking, why does this matter? Fair question. It matters because if a disease is rare, fewer resources will be allocated to treating it. Not only that, but it is also less likely a GP will know about rare diseases than common ones. And for many people, their GP is the first professional they talk to. We know early detection is key to managing the condition, so we need it to be visible.
For people, trying to access information, it can be hard because of all the terms and methods. Science is not known for its clarity and openness, but some people want that to change. It is essential to understand where our information comes from and how we collect it. In the future, it will be crucial to our health as a society. It’s the only way people can trust in medicine.
I hope you will take away from this article that there are different kinds of statistics. And next time you read a paper; you will understand better what it is saying. I want you to ask questions and feel empowered to take control of your health as a result.
About the Author
Shannon Sweeney is a psychology and sociology student from Ireland. She is also living with HS and has a keen interest in lifestyle, wellbeing, and Hidradenitis Suppurativa.