A study showed an association between intentional weight loss ...

Question

A study showed an association between intentional weight loss and a decreased risk of high blood pressure. Is it appropriate to infer from this study that weight loss causes a decreased risk of high blood pressure? Explain. (Source: European Association for the Study of Obesity)

Accepted Answer

Hello there. Today we're gonna solve the following practice problem together. So first off, let us read the problem and highlight all the key pieces of information that we need to use in order to solve this problem. A survey reports that people who drink green tea regularly have a lower incidence of heart disease. Can we conclude that green tea consumption causes a reduction in heart disease risk? Select the most accurate statement. Awesome. So it appears for this particular problem, we're asked to determine whether or not we can conclude that. Green tea consumption does indeed cause a reduction in the chance of contracting heart disease. Or rather developing heart disease. So does green tea consumption cause a reduction in heart disease risk? So that's what we're trying to determine. And in order to determine that, we're asked to look at our multiple choice answers and choose which one is the most accurate statement. So now that we know what we're trying to solve for, let's read off our multiple choice answers to see what our final answer might be. A is yes, because the survey proves causation. B is yes because green tea is healthy. C is no because association does not imply causation in observational studies, and D is no because heart disease is genetic. So with that in mind. Our first step that we need to take in order to solve this problem is we need to identify the type of study that is being used for this particular prompt, and with that in mind, we need to note that based on what the prom tells us, the statement says a survey was conducted, and as we should recall, a survey is a type of observational study, not an experiment. And as we should recall, in an observational study, researchers observe outcomes without assigning treatments or interventions. With that in mind, our second step is we need to understand our findings. So, as we should recall, the finding is an association between green tea consumption and a lower heart disease rate. And association, as we should recall, means two variables are related to one another, but not necessarily through a cause and effect relationship. So our 3rd step now is we need to recall the key principle. So, once again, we need to note, this is very important, that association does not imply causation. And just because two things happen together, meaning people who drink green tea have lower heart disease risk or have lower heart disease risk developing, whatever, this does not mean that one causes the other. So, with that in mind, We need to also note that there may be a confounding variable, meaning green tea drinkers may also eat healthier, exercise more, or be wealthier, factors that also may help reduce heart disease risk. So we need to, once again, we need to recall that there might be confounding variables at play. And in order to prove causation, as we should recall, we need a controlled experiment, meaning we need a randomized clinical trial. So with that in mind, our final answer without a doubt will have to be multiple choice answer letter C, which once again is no, because association does not imply causation in observational studies. And that's it. That is our final answer. Thank you so much for watching. Hopefully that helped, and I can't wait to see you in the next video. Bye.

A study showed an association between intentional weight loss and a decreased risk of high blood pressure. Is it appropriate to infer from this study that weight loss causes a decreased risk of high blood pressure? Explain. (Source: European Association for the Study of Obesity)

Key Concepts

Correlation vs. Causation

Confounding Variables

Study Design

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