Retrospective vs Prospective Study: Advantages, Types and Differences.
https://www.cognibrain.com/retrospective-vs-prospective-study-advantages-types-and-differences/
2. What is a Retrospective
Study?
Retrospective, the term comprises two words i.e.
“retro” which means “in the past” and “spective”
which means “to look”. Thus, a retrospective
analyzes the events of information that had
already occurred in the past. In a retrospective
study, the outcome of the reference studies has
already occurred before a retrospective study is
initiated. The researcher or an author of a
retrospective study can collect the data from the
registry. In a retrospective study, after the
collection of data, the research question is framed.
3. What are the Advantages of
Retrospective Study?
Less time consuming and
cheaper: Retrospective studies are cheaper and
require less time for completion. As the data
related to the study is already available and the
researcher compiles and compares the data
between and subjects and control, retrospective
studies provide immediate results.
Effective in rare disease: Retrospective study is
quiet effective in rare diseases. Data related to the
rare disease is available from various centres to
arrive at an evaluable study population.
4. Initial screening: Sometimes the retrospective
studies are done as an initial screening for
prospective studies.
No-follow-up: Retrospective studies uses the
data already available in the literature or the
registry. Thus, there is no risk of loss of
follow-up in retrospective studies.
Large data-set: Retrospective makes use of
large data-set. This may provide more accurate
results.
5. What are the Types of
Retrospective Studies?
Retrospective cohort studies: This study is also
known as the historic cohort study.
Case series and case reports: Case reports are a
type of retrospective study in which the
researcher reports symptoms or instructive case
that was not previously seen with a medical
condition.
Case-Control Studies: Case-control studies are
better than case series and case reports.
6. What is a Prospective Study?
Prospective studies are done in the present to
analyze the outcome in the future. In the
prospective study, the information is required to
be generated and is not available before the start
of the study. An example of a prospective study is
to follow-up with a group of alcohol drinkers to
identify whether drinking alcohol for 10-years is
linked to liver disease. It is to be noted that none
of the subjects enrolled under the study should
have the outcome of interest. For instance, in the
above example, none of the subjects should have
liver disease before the start of the study.
7. What are the Advantages of
Prospective Study?
New disease risk factors: Prospective studies
are important in analyzing the risk factors for
new diseases for which the data is not available.
This will help in the effective management of
the disease.
Accurate results: Because of well-controlled
study design and accurate generation of data, the
results provided by prospective studies are
relatively more authentic.
8. Detailed data analysis: Detailed analysis of
the outcome and other statistical factors can be
done in prospective studies. Exposure can be
measured before the outcome and the incidence
and disease process can also be determined.
Multiple outcomes: Multiple outcomes can
also be obtained from prospective studies.
No risk of recall bias: As the prospective
study does not require any data recollection
from the past, the risk of recall bias is
eliminated.
9. What are the Various Types of
Prospective Studies?
Prospective trend studies: In this study, the
samples are taken from the dynamic population in
which the individuals change over time.
Prospective panel studies: In such studies, the
measurement is done on the same set of
individuals.
Prospective cohort studies: In the prospective
cohort studies, the measurement is done on the
individuals from the same pool of individuals.
10. What is the Difference between
Retrospective and Prospective Study?
Data: In the prospective study the data is generated
by the researcher after enrollment of the subjects
while retrospective studies make use of the already
available information.
Control: Prospective study has more control over
the subjects and data generation as compared to
retrospective studies.
Accuracy: More accurate results are provided by
prospective studies due to less biasness and
optimum data control.
11. Time and cost: Prospective studies are more time-
consuming and costlier as compared to
retrospective studies.
Biasness: The risk of recall biasness is eliminated
in prospective studies.
Practicality: Prospective studies are both
observational and interventional while
retrospective studies are only observational.
Usefulness: Prospective studies are useful in cases
of emerging new exposures while retrospective
studies are not of much use in such scenarios.
