The document discusses case-control studies and cohort studies as two types of epidemiological research used to understand disease causes and risk factors. Case-control studies compare existing groups based on certain attributes and are less expensive and time-consuming, but they may produce less reliable evidence. In contrast, cohort studies follow a group over time to observe health outcomes and establish disease links, providing more comprehensive insights into disease causation.

1. Case Control Study

2. Introduction
 Epidemiology and cause of disease is understood and
determined by two types of study-cohort study and case-control
study. Case control study is a type of observational or
ecological study where two existing groups are compared on
the basis of certain attributes
 It is a type of epidemiological observational study that is used in
the field of medicine. It is frequently compared with cohort
studies which will be discussed further. As it is an
epidemiological study, it increases the power of study
 Case control study is initially analyzed by testing various factors
like relative risk, odds ratio and also disease assumptions

3. Cohort Study
 Cohort study is a type of medical research used to analyze the cause of disease and
establishing the links between risk factors and health outcomes
 Cohort studies are also known as “prospective” studies i.e., they are planned in advance
and carried out in future for a period of time. To tell in general, this study is projected
towards future. Cohort studies are forward-looking
 In this type of study, researchers raise a research question and thus find a hypothesis
about the causes of the disease. Then, they observe a group of people over a certain
period of time, collect data and detect the changes that happen within them. Cohort
studies are used by epidemiologists looking into the factors that affect individual health
and illness
 Some of the terms that describe cohort studies include incidence, longitudinal, historic
and forward-looking. This study finds the cause and roots of the particular disease and
hence proved to be more advantageous

4. Cohort Study Vs Case Control
Study

5. Case Control Study Vs
Retrospective Cohort Study

6. Advantages
 Case-control studies are inexpensive and are carried out by
small terms and by individual researchers
 They are invented in such a way that they are always in a
stage of advancement
 Case-control study is inexpensive when compared to that of
the cohort studies
 They have greater statistical power and hence provide
accurate answers for the observations made
 It is less time-consuming process.
 They are effective for rare diseases and long latency period
exposure of disease

7. Disadvantage
 Case-control studies do not provide more evidence when
compared to other observational studies and hence the
chance of confusions of various factors can arise and
assumptions of disease may be extended
 When the risk factor arises, there occurs a problem to extend
the timeline for the exposure of disease and in the outcome
status
 One of the major drawbacks is that this study is more difficult
to obtain the reliable information about individual’s health
issues and conditions. Hence, this study is placed low in the
hierarchy of evidence
 They are used only in selection basis
 They prove to be ineffective in rare exposures

8. Conclusions
 Various types of studies related to the medicine
and epidemiological research has been
discussed and their comparisons have been
studied. Still there are various advancements to
be done in this field for the betterment of
improvement in medical health

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