What does it mean when an observational study is retrospective? What does it mean when an observational study is prospective? What does it mean when an observational study is retrospective? A. A retrospective study is a list of all individuals in a population along with certain characteristics of each individual. B. A retrospective study requires that individuals look back in time or require the researcher to look at existing records. C. A retrospective study collects the data over time. What does it mean when an observational study is prospective? A. A prospective study is a list of all individuals in a population along with certain characteristics of each individual. B. A prospective study requires that individuals look back in time or require the researcher to look at existing records C. A prospective study collects the data over time.
The correct answer and explanation is:
The correct answers are:
Retrospective Study:
B. A retrospective study requires that individuals look back in time or require the researcher to look at existing records.
Prospective Study:
C. A prospective study collects the data over time.
Explanation :
An observational study investigates outcomes without manipulating any variables directly. Observational studies can be categorized into retrospective and prospective based on the timing and direction in which the data is collected.
Retrospective Observational Study
A retrospective study involves analyzing existing data from past events. Researchers begin with an outcome of interest and trace back through time to identify exposures or factors that might have influenced that outcome. This method relies heavily on previously recorded information such as medical records, historical data, or patient recollections. Because it uses existing records, retrospective studies can be relatively quick and cost-effective. However, they are often limited by the accuracy, completeness, and potential biases within historical data, since researchers have no control over how that data was originally collected.
For example, if researchers want to investigate the factors associated with a specific disease, they might review medical records of patients who already developed that disease and analyze their historical exposure to various risk factors.
Prospective Observational Study
In contrast, a prospective observational study collects data from individuals moving forward in time. Researchers define a population and variables of interest before the outcomes occur. Participants are followed over a defined period to observe if and when certain outcomes develop. This approach allows for a more controlled and structured data collection process, potentially reducing biases found in retrospective studies. Prospective studies often provide more reliable data because the information is collected consistently according to a pre-established protocol.
For instance, a study tracking a group of individuals’ dietary habits over several years to determine their impact on heart disease risk would be prospective. Researchers would document diet and lifestyle choices continuously, then measure outcomes at the end.