Please answer the following questions, support your answer with . 1.              Define the descriptive and analytic study design. 2.              What is the difference between them? 3.              What are the sub-group of descriptive and analytic study design? 4.              Which study design answer what, who, where, and when; and which one answer why and how?

1. Descriptive Study Design:
The descriptive study design aims to provide a comprehensive portrayal or description of a specific phenomenon or population. It involves collecting data and summarizing it in a way that can be easily understood and interpreted. Descriptive studies often focus on the prevalence, distribution, and characteristics of the variable(s) being investigated. This design does not involve manipulation of variables or testing cause-and-effect relationships.

Analytic Study Design:
On the other hand, the analytic study design is used to examine the relationships between variables, investigate cause-and-effect relationships, and test hypotheses. This design involves manipulating or observing variables to determine the impact or effect they have on an outcome of interest. Analytic studies are more focused on determining the associations, correlations, and causal relationships between variables.

2. Differences between Descriptive and Analytic Study Design:
The main difference between descriptive and analytic study designs lies in their objectives and methods. Descriptive studies aim to provide a comprehensive description of a phenomenon, while analytic studies aim to investigate cause-and-effect relationships and establish associations between variables.
Descriptive studies are primarily concerned with presenting data in a clear and concise manner, such as through summary statistics, frequencies, and visual representations. These studies focus on the “what” and “how much” aspects of a phenomenon.
On the other hand, analytic studies employ more in-depth statistical analyses to determine the relationship between variables. They investigate the “how” and “why” aspects of a phenomenon, aiming to establish causal relationships. Analytic studies involve comparing groups, testing hypotheses, and employing more sophisticated statistical techniques.

3. Sub-groups of Descriptive and Analytic Study Design:
Sub-groups of Descriptive Study Design:
a) Cross-sectional studies: These studies collect data at a specific point in time to describe the prevalence or characteristics of a condition or behavior in a population. They provide a snapshot of the population at that particular time.
b) Case series studies: These studies describe the characteristics and outcomes of a group of individuals with a particular condition or who have undergone a specific treatment. Case series studies often involve retrospective or prospective data collection.
c) Ecological studies: These studies examine the relationship between exposure and outcome at the population level, rather than at the individual level. They explore associations between population-level variables and health outcomes.
d) Case reports: These studies provide detailed and individualized descriptions of a single case, often highlighting rare or unusual conditions or treatments.

Sub-groups of Analytic Study Design:
a) Cohort studies: These studies follow a group of individuals over time to determine the association between exposure and outcome. They can be prospective or retrospective and are often used to examine the development of diseases or health conditions.
b) Case-control studies: These studies compare individuals with a particular outcome (cases) to individuals without the outcome (controls) to determine the association between exposure and outcome. They are useful for investigating rare or long-term outcomes.
c) Interventional/experimental studies: These studies involve the manipulation or randomization of variables to determine causality. Examples include randomized controlled trials (RCTs) and quasi-experimental designs.
d) Longitudinal studies: These studies collect data from the same individuals over an extended period to examine changes or trends in variables of interest. Longitudinal studies can be descriptive or analytic, depending on their objectives.

4. Study Design and the types of questions they answer:
Descriptive study designs, such as cross-sectional studies, case series studies, and ecological studies, are best suited to answer questions regarding “what,” “who,” “where,” and “when.” These designs provide a snapshot of a population or phenomenon, describing its characteristics, prevalence, and distribution. They are useful for generating hypotheses and identifying patterns.

Analytic study designs, including cohort studies, case-control studies, and intervention/experimental studies, are better equipped to answer questions related to “why” and “how.” These designs allow researchers to investigate the causes, associations, and underlying mechanisms of a phenomenon. They involve manipulating or observing variables to establish causal relationships and test hypotheses.

In conclusion, descriptive study designs focus on describing a phenomenon or population, while analytic study designs focus on investigating cause-and-effect relationships and establishing associations between variables. Each type of study design has sub-groups that allow researchers to address different types of research questions and objectives. Descriptive study designs answer questions related to “what,” “who,” “where,” and “when,” while analytic study designs answer questions related to “why” and “how.”