There are various research study design types, each with specific advantages and disadvantages. The research question’s nature and the resources available will determine the study design that will be used to address that question. We give an overview of research study designs and their classification in this article, which is the first in a series on “study designs.” The subsequent articles will focus on individual designs.
There are many different types of research study designs, each with advantages and limitations. The nature of the question, the purpose of the research, and the accessibility of resources all influence the type of study design that will be used to address a specific research question. Understanding the various study design types, as well as their advantages and disadvantages, is crucial because the study’s design can impact the validity of its findings.
Many research studies evaluate the connection between two variables. The key here is to determine whether one variable is related to or accountable for changes in the other variable’s value. The risk factor whose impact is being studied is referred to as exposure (or intervention). Additionally, it is known as the independent or predictor variable. The exposure (or intervention) causes the outcome (or predicted or dependent) variable to change. When the “causative” variable is naturally determined (as in observational studies, where examples include age, sex, smoking, and educational status), the term “exposure” is typically used; however, the term “intervention” is preferred when the researcher assigns some or all participants to receive a particular treatment for the purpose of the study (experimental studies – e g. , administration of a drug). Before the study began, if a drug was started in some participants but not in the others, this counts as exposure rather than intervention because the drug was not started specifically for the study.
What is a retrospective study?
A research project known as a retrospective study examines the outcomes of exposure to and developments of medical incidents that have already happened. Researchers conducting this study are also curious about participants’ development of a specific medical condition, much like a prospective study. In order to study the subjects’ exposure status and medical outcomes, they use this data to identify and create a cohort of people who were predisposed to the condition in question. Typically, researchers create new analyses and conclusions about the outcome of interest using preexisting data.
What is a prospective study?
A prospective study is a scientific investigation carried out by researchers to find out more about a specific medical subject. In this study, a particular cohort of participants is involved who are predisposed to the desired outcome. This indicates that data is gathered and analyzed by researchers with the intention of creating medical treatments or monitoring the development of a disease. Additionally, researchers can plan studies, gather participant information, and gather baseline exposure data before their research subjects experience a medical condition.
For instance, researchers might conduct a prospective study to understand how individuals who are predisposed to a certain virus may respond to exposure without actually contracting the virus. Prospective studies are frequently long-term, which means that researchers follow up with participants or keep tabs on their health over time to see if they develop the condition under investigation.
A prospective vs. a retrospective study
There are a number of differences between the two cohort study types, including the following:
Data collection
Data collection is the main distinction between retrospective and prospective studies. Researchers examine the information already available regarding exposure factors and their effect in a retrospective study. Additionally, researchers may use materials that have already been documented or published, such as journal articles and medical reports.
In order to collect data for a prospective study, researchers must conduct their own interviews and observations. This enables the researchers to be present during exposure to see the effects of exposure up close. Because a prospective study involves events that have not yet happened, it is likely that there are no records of the incident of interest.
Data analysis
Given that the methods for gathering data for prospective and retrospective studies vary, the procedures for data analysis also vary. If there is sufficient data in documents and medical reports to draw a conclusion, a researcher can analyze the data in a retrospective study right away. The amount of data the researcher can gather and how the research is carried out may affect how quickly they can analyze their data or draw a conclusion for a prospective study.
Use and purpose
Typically, the goal of a retrospective study is to expand on a recent discovery, supplement existing research, and provide new information. Retrospective studies are used by researchers to determine why something occurred and to explain a current occurrence or discovery. Because they are future-oriented and seek to predict whether an event will occur, prospective studies are different from other types of research.
Either type of research can be used by scientists to learn more about a specific topic. The methodology used in the two study types differs significantly. Researchers may conduct a retrospective study to look into the circumstances surrounding an illness outbreak if they are curious to learn what caused it. Alternately, if they’re curious about how treatments affect people with the illness, they could use a prospective study.
Time and cost
Retrospective studies typically cost less and take less time than prospective studies. This is so that less time and money are spent on data collection since a retrospective study doesn’t involve watching and interviewing participants. Data are easily accessible for collection and analysis in a retrospective study, necessitating a smaller research team and fewer resources.
Prospective studies are frequently longitudinal, which means they monitor and assess participants’ responses to exposure over a predetermined period of time. In a prospective study, in addition to the usual data collection and analysis, researchers may contact and recruit participants and gather background information.
Advantages and disadvantages of a prospective study
Advantages and disadvantages of a prospective study include:
Advantages
Three advantages of a prospective study are:
Disadvantages
Three disadvantages of a prospective study are:
Advantages and disadvantages of a retrospective study
Advantages and disadvantages of a retrospective study include:
Advantages
Three advantages to a retrospective study are:
Disadvantages
Three disadvantages of a retrospective study are:
Retrospective vs Prospective – Observational Study – AP Stat
FAQ
Why is a prospective study better than a retrospective study?
Retrospective and prospective are fundamentally different from one another because retrospective refers to looking backwards (into the past), whereas prospective refers to looking forward (into the future). When describing cohort studies, we primarily use the two adjectives retrospective and prospective.
What is the difference between a retrospective study and a prospective study apes?
Retrospective studies typically have more sources of bias and confounding, whereas prospective studies typically have less. A retrospective study examines exposures to potential risk or protective factors in relation to a predetermined outcome by looking back in time.
What is a prospective study?
The study goes back in time to when they were healthy, and information from this period leading up to the result is gathered and analyzed to understand how the disease/condition started and progressed. On the other hand, in prospective studies, the result has not yet occurred at the time of the study.
