What is the Difference Between Retrospective and Prospective

The main difference between retrospective and prospective is that retrospective means looking backwards (into the past) while prospective means looking forward (into the future).

We mainly use the two adjectives retrospective and prospective when describing cohort studies. A retrospective cohort study is a study where researchers comparatively study the historical data of a group of people who have a particular disease and a group of people who do not have that disease. A prospective cohort study, on the other hand, is a type of study where no one in the sample has the disease being measured when the study commences.

Key Areas Covered

1. What Does Retrospective Mean
     – Definition, Features, Study
2. What Does Prospective Mean
     – Definition, Features, Study
3. What is the Difference Between Retrospective and Prospective
    – Comparison of Key Differences

Key Terms

Cohort Study, Retrospective, Prospective

What Does Retrospective Mean

Prospective means looking back into past events or situations. The adjective retrospective is used in many fields, including medicine, law, and arts. As a noun, retrospective refers to a compilation showing the development of an artist’s work over a period of time. In medicine, a medical retrospective can refer to a patient’s medical history and lifestyle.

In academics as well as in medical research, a retrospective study refers to a study that examines backward in time, generally using medical records and interviews with patients who are already known to have a disease. This type of research uses historical data. For example, a retrospective study may involve analyzing the lifestyle choices and medical history of a group of 100 people with type 2 diabetes. Then the researchers also study a second group of 100 people without type 2 diabetes, and then compare the two groups.

What Does Prospective Mean

Prospective is an adjective that means “relating to or effective in the future”. We usually use this adjective to refer to something that is likely to happen in future. Therefore, a prospective study is the opposite of a retrospective study. This type of research looks into the future.

A prospective cohort study is a type of longitudinal study that follows a group of similar individuals over a long period of time. At the start of the research study, no one in the sample is suffering from the disease under study. In other words, researchers enrol the participants before they develop the disease in question. However, it is expected that some of the participants will develop the disease in the future. Following a group of 100 people with high-risk factors for lung cancers ten years to see if they develop the disease is an example of a prospective study.

Difference Between Retrospective and Prospective

Definition

Retrospective means looking backwards (into the past) while prospective means looking forward (into the future).

Cohort Study

A retrospective study is a type of cohort study that analyzes two groups of people: those with the disease under study as well as a very similar group of people who do not have the disease. A prospective study, on the other hand, is a type of cohort study where the researcher enrol participants into the study before they develop the disease or outcome in question.

Disease in the Sample

A retrospective study involves a group of people who already have the disease under study, while a prospective study involves a group of people who don’t have the disease under study.

Conclusion

Retrospective means looking backward (into the past) while prospective means looking forward (into the future). A retrospective cohort study is a study where researchers comparatively study the historical data of a group of people who have a particular disease and a group of people who do not have that disease. A prospective cohort study, on the other hand, is a type of study where no one in the sample has the disease being measured when the study commences. Thus, this is the main difference between retrospective and prospective.

Reference:

1. “Cohort Study (Retrospective, Prospective): Definition, Examples.” Statistics How To, 2 Apr. 2018, Available here.