#Types of retrospective studies how to#

In observational studies, scientists observe and gather data on some phenomenon that's already happening: patterns of olive oil consumption, who tends to take vitamin D supplements, how much people exercise, and so on. Much of health research - especially the kind that makes the news headlines - can be broken down into two basic types: observational and experimental.

Here's a quick guide to understanding study design that will help you navigate the often bewildering world of health research.ġ) Much of health research can be broken down into two types: Observational and experimental studies When a news story suggests, 'A new scientific study has found.' or a celebrity doctor begins a sentence with, 'Studies show.', you need to ask, 'What kind of studies?' Because 'studies' are not equally reliable, they all have different limitations, and they should not be acted on in the same manner - or even acted on at all.

There are literally thousands of ways to design a study. The grain study, like many other health studies you read about, is an excellent moment to think about one key insight that could help you live longer than whole grains (or red wine or coffee or chocolate) ever will: a study isn't a study isn't a study like any other. Their results match those found in the Iowa Women’s Health Study and the Norwegian County Study, but they did not fully align with other studies involving diabetics and healthy older people. For example, this study didn't account for key determinants of health like wealth and education, which may be more important for the health of whole grain eaters than what they eat.īesides, as the study authors themselves point out, theirs is not the only word on this matter. Studies can control for many possible ' confounding factors ' - or variables that may influence a particular outcome -but it's impossible to account for everything that may matter. Whole grains probably won't save your life. In this case, the study population was not randomly assigned to eat more whole grains, which means we can't know whether the people who ate them are healthier because of their diet or because of other traits they share, like their age, ethnicity, smoking status, alcohol intake, physical activity levels, multivitamin use, and family medical history.

#Types of retrospective studies how to#

While this latest work represents excellent science - a prospective cohort observational study, in scientific parlance - it's just one study. And when you look at a single study, you're getting only one piece of the puzzle, one interpretation of the research question, one idea about how to run a scientific experiment. Many news sources are going to have headlines like ' Whole grains lead to heart-healthy benefits' and ' Whole Grain Consumption Lowers Death Risk.'īut you shouldn't believe them. Today, the prestigious academic journal JAMA Internal Medicine published an article on the association between eating whole grains and having a lower risk of death from cardiovascular disease.