A prospective study refers to a group or cohort study, which aims to investigate the cause of disease. Also, it develops the connection between risk elements and health outcomes. The students or researchers plan prospective study in advance and conduct that over a particular time.
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Features of the Prospective Studies
- Prospective or cohort study normally observes a large group of people. It monitors their exposure to particular risk factors to get hints about the probable cause of disease.
- The researchers gather data as the research advances. This concept is in contrast to that of the retrospective study, in which the students work on prior research or collected data.
- One of the notable examples of prospective study is the Nurses’ Health Study. This study has already established several essential connections between daily life choices and health by observing hundreds of thousands of females in North America.
- This study may also be useful to determine social factors that influence health.
Investigating Causes
- Cohort or Prospective studies monitor or observe a large group of individuals to investigate the cause of disease.
- The prospective study design is an effective scientific method to measure the outcomes of a suspected risk element.
- In this type of study, researchers come up with a question and develop a hypothesis about the potential cause of a disease.
- They monitor a group of individuals for a particular period, for example, several years. They gather data that relates to the disease.
- Through this process, they plan to find out any variations in health, which may relate to the probable risk factors they have noticed.
For instance, scientists may require participants to note particular lifestyle routine during the research. Later, they may evaluate any possible connection between lifestyle factors and disease.
Also Read: Advantages and Disadvantages of Prospective Study
Comparative Analysis of Prospective Study
Cohort or Prospective studies base on observation. The researchers monitor and observe the events without any intervention.
On the other hand, Randomized, Controlled trials employ investigating interventional drugs. For example, a new medicine, but it is not always viable to use them for investigating the cause of diseases.
However, in RCTs, the scientists intervene and give participants the new medicines to evaluate the outcomes. When assessing the causes of the diseases, it is unethical to expose members to a particular risk factor knowingly. Nevertheless, this is how RCT works; these trials may harm the patients instead of giving them benefits.

In case, the drug has already gone through a testing phase, and it may not cause any harmful effect on the patient. Sometimes, researchers are sure that a particular drug is safe enough to try; in this situation, it would be ethical to expose the participant to that drug. In some cases, participants also agree to become part of a trial as they think that using a particular medicine may improve their condition.
A case-control study is another observational research technique, which investigates the cause of disease.
Prospective or cohort studies are better as compared to case-control studies. The prospective study uses a large number of group or individuals for observational research. In contrast, the case-control study is retrospective, i.e. it involves a limited or small number of individuals.
Examples
A few prospective studies have been extensive and lasted a long time. Importantly, these studies succeeded in delivering useful data that serve researchers in various fields.
Nurses’ Health Study
It is a popular example of prospective research. The purpose of this study was to analyze women’s health for the long-term. Originally, this research began in 1976 to evaluate the long-term implications of oral contraceptive usage.
The study enrolled the second generation for the Nurses’ Health Study II in 1989. Furthermore, it recruited the third generation nurses’ cohort from different parts of the United States and Canada in 2010.
The first group of NHS comprised of married women in the age group of 30-55 years. The NHS II and NHS III planned to observe a more diverse unit by recruiting women aged from 20 to 46 years.
As a result of this study, researchers have succeeded in getting some significant insights into health. “Medical News Today” (MNT) published the following findings of this research:
- Nuts may be helpful in the prevention of heart diseases.
- Obesity or weight-gain during early adulthood may cause health complications in later life.
Also, the research raised the following question about Colon Cancer:
Can Pro-inflammatory Diets Contribute to Risks?
Prospective or cohort studies are suitable in finding the connection between health and environmental factors, for example, food and water, and chemicals in the air. For these issues, the World Health Organization (WHO) facilitates researchers to conduct large-scale prospective research.
Gathering data from various studies may increase the sample size, and it might make the outcomes more reliable, particularly for specific conditions, for example, a few types of cancer.

Limitations
Although prospective studies have been useful in medical research, they are not always the ideal form of observational research. A prospective study has some limitations:
- It is not still suitable to find clues about rare disease.
- This type of study is generally not suitable to find the cause of the unexpected outbreak of diseases. In contrast, case-control research may give robust results.
- It is costly to run and may take several years or even decades to give results.
- It may give clues regarding the cause of disease; it does not provide substantial evidence of the connection between risk elements and health.
- Participants may quit the group or probably die of the cause, which is not under research.
Final Word
A prospective study is observational research in which researchers study a large no. of individuals to investigate the cause of a particular disease. It is a long-term process that may take several years or even decades.
Through this study, the researchers try to establish a link between risk factors and diseases. After a particular time, researchers may come up with their findings or a research question. The study has some limitations as it takes plenty of time, and it is costly to run.