Chapter 4, Problem 1QC

Health clinics sometimes cite retrospective studies to support their claim that the lipodissolve technique is safe. What is a “retrospective study”? How is it different from a controlled study?

Summary Introduction

To review:

The retrospective study and its difference with a control study.

Introduction:

Everyone wants a fat free perfect body but that is not easy to achieve. This fantasy of having a perfect body is being used by many health clinics, they show retrospective studies to patients to make them believe that methods like Lipodissolve are safe and effective.

Explanation of Solution

The retrospective study investigates the effect of an exposure factor in a group of individuals and compares the result with another group of individuals who are not exposed to that exposure factor. A retrospective study looks backward so it is also known as a historical study. It is used in medical and psychological research.

The difference between controlled study and retrospective study:

Controlled study	Retrospective study
The outcome of the study is unknown at the start of the study.	The outcome is already known at the start of the study.
It will try to determine the possible exposure factors that may cause the known outcome.	It will just compare the risk of developing the outcome to some already known exposure factors.
It is expensive and more time consuming.	Less expensive and less time consuming.

Conclusion

Therefore, it can be concluded that even though retrospective studies are useful in medical and psychological research, it cannot predict the effectiveness of a drug.