Study designs Flashcards
What is a study design?
A structured framework used to collect, analyze, and interpret data in research.
What is a descriptive design?
It describes the occurrence of disease/health related conditions
What is an observational design?
To simply watch and record what happens naturally, without actively manipulating any variables.
What is an analytical design?
Describes and further analyses the relationship, investigating association between exposure and outcome
What is an experimental design?
Researchers introduce a treatment or intervention and determine effectiveness
Differentiate between incidence and prevalence
Prevalence: Number of cases in a population
Incidence: Number of new cases in a population
Explain the cross sectional design
-Participants recruited based on inclusion and exclusion criteria
-Study the exposure and outcome at the same time
-Estimate the prevalence of outcome and exposure as well. Calculate the odds ratios
What is the goal of a cross sectional design
To identify the prevalence of a particular risk factor or disease
What are the strengths of a cross sectional design?
- Relatively easy, faster and inexpensive
- Assess health care needs of a population
- Evaluates relationship between exposures that are fixed characteristics of an individual and outcome
- Assessing relationship between exposure and outcome before costly designs
What are the limitations of cross sectional design?
- Difficult to derive casual relationships
- Limited use in drawing causal relationship
Describe the cohort design
-At the start of the research, we gather up participants who are free of disease. they are then exposed to a certain risk factor
-Then we gather up data on what their outcome might be
-Then we determine whether or not the risk factor does play a role in the outcome
What are the strengths of the Cohort design?
-Establishes causal relationship
-Determines incidence of a disease
-Measures the risk of enveloping the disease as well as the incidence of the disease
What are the limitations of the cohort design?
-Prospective design takes long and is expensive
-Not ideal for rare diseases and it will need big sample
-Loss to follow up
-Information bias
Describe the case control
Used to investigate causes of rare disease, including the cases and control comparison group.
What are the strengths of case control
- Efficient for rare disease
- Less expensive and time-consuming compared to Cohort
- Can be used to identify potential risk factors
What are the limitations of case control
- Different recollections of past exposure, potentially distorting the results
- Choosing appropriate controls can be challenging, potentially introducing bias
- Cannot calculate incidence
- Difficult to determine whether exposure occurred before disease developed, making it challenging to establish causalty
