What is a Case Control Study

A case control study is a type of observational study where two existing groups with different outcome are compared on the basis of a causal attribute. This is a very broad definition because sometimes we discover that the casual attribute has no relation at all after the study is complete, and sometimes we discover that the two existing groups actually have very similar or the same outcome, but we didn’t know until the end of the study.

what is a case control study

A Case Control Study

Sometimes, the best way to explain a case control study is with an example. There was rather an “Icky” case control study that was part of an investigation into hepatitis A in Switzerland and Australia. What happened was that sudden occurrences of hepatitis A occurred in small pockets of people in Australia and Switzerland. What was alarming about these cases was that they existed in small infection pockets, with a high incidence in a small area, and some of the infected had never had any sexual contact with another human. Numerous case control studies narrowed the cases down, and it turned out that the culprit was frozen berries!

Case control studies helped identify that the disease was not being spread sexually, and after lots of investigation and case control studies, it was discovered that the berries were the cause. In many cases, the links between each study seemed weak, but as each link was found, it helped investigators narrow down their investigation.

In short, it turns out that an eastern European country was picking berries, and its STI-infected staff was not washing their hands after using the toilet. It was thanks to a case control study that this revelation was discovered. Many studies were undertaken as to how the berries were picked, why other berries were not infected, and why people in different countries were being infected.

The infection spread so far and yet in small pockets because of the berries being sold in stores in the countries. A study regarding how berries were harvested was also linked with the STI cases, and eventually, the full facts were discovered.

Without the undertaking of many case control studies, the links between these events would have never been discovered. Even things like how the berries that were harvested mechanically were never infected would not have been spotted if a case-control study were not undertaken between hand-picked soft fruit and mechanically harvested tougher fruit.

What is a Case Control Study?

As per the example above, you take the work of two different studies that “May” be related in outcome, or that may have a link, and you investigate them side by side.

For example, you may take a study on how much people smoke and how it affects their athletic ability. You may also take a study on how many people who do lots of exercises are less prone to lung cancer.

In this example, the only link/casual attribute is athletic ability/exercise, but when these studies are used in case control studies, a link between smoking and lung cancer starts to appear.

As you can imagine, the researchers compare exercise and athletic ability, and suddenly notice that the people who do less exercise are typically smokers, and another study shows that people who do less exercise are often smokers, and suddenly a link between one study and another becomes more and more apparent.

It is just like the previous example where a study into the cleanliness of the eastern European company’s employees was compared and contrasted with a study on the spread of STIs, and the link between employees washing their hands and infection suddenly became obvious.

Getting It Right the First Time

If you are struggling with your case control study, have you considered the GradeCatcher’s partners service? The writers on staff have years of experience, and each member has at least a degree qualification. They were as good as writing the case-control study definition, since they have teams who work on case-control studies week after week. Do not shy away from getting help from professionals.

One problem you may have is how you find casual attributes between one case study and another, and the fact is that you cannot predict what your results will be. After all, nobody ever predicted that the spread of infection in Switzerland would have anything to do with the bathroom habits of berries pickers thousands of miles away. Just remember that it is not your job to come up with breakthroughs. It is your job to clear the path for the people who will one day stand on your shoulders.

If you complete 100 case control studies and find no links, then you have helped ensure that future scientists do not waste their time doing the same studies. You have still moved progress forwards, even if it feels like you are standing still.