Lecture 1: Intro Flashcards
What is biostatistics?
Biostatistics is the application of statistical tools in health sciences
Biostatistics is a growing field with many applications in Medical sciences, Epidemiology, Environmental sciences and educational research.
True or false?
True
How is biostatistics applied in healthcare?
- Conducting medical research
- Understanding medical/epidemiological problems
- Appraise/interpreting the literature
- Clinical decision making
- Interpreting vital statistics
- Determining health policy
- Implementing diagnostic procedures
What is data/observations?
Observations/data are obtained from individuals.
What is a population?
A set of all individuals of interest
Data types determine?
The choice of analysis
What are the two types of data?
Categorical - qualitative
Numerical - quantitative
What is categorical (qualitative) data?
Data describing qualities, places, individuals in distinct groups
- Names and labels are used
- Categories are created based on characteristics
Examples:
Marital status
Eye color
Pain severity
Smoking status
What is Numerical (quantitative) data?
Data that can be measured and expressed numerically
- Data are always in the form of counts or measurements
- Data are always numeric
Numerical (quantitative)data can be divided in?
Discrete- counts
Continuous - measured
What is Duscrete data?
Can only take on certain values
Examples:
Number of kids
Number of heart beats
What is continuous data?
Can take on any value in a continuous scale
Examples:
Height
Age
Weight
Stevens claimed that all measurements were based on four types of scales
Nominal
Ordinal
Interval
Ratio
What are the types of scales?
Nominal scale
Ordinale scale
Interval scale
Ratio scale
What is the Nominal scale?
- Classifications of distributions
- No magnitude or order
- Examples: ethnicity ( White-British, Afro Caribbean, Asian etc)
What is the Ordinal scale?
- Any scale that is ordered
* Examples: aggression (weak, moderate intensity, strong)
What is the Interval scale?
- Any scale of measurement with no absolute zero point, equal intervals
- Example: Temperature
What is the Ratio scale?
- Any scale with equal intervals, absolute zero point
* Example: Weight, Height
What is the Binary or dichotomous variable?
Answers can take only two possible values
•Do you own a car? “yes” or “no”
•Does a patient have diabetes “yes” or “no”
What is the independent vs dependent variable study?
Study set up to measure the effect of one variable on another
What is the Independent variable?
Variable we expect to have an I,pact
Sometimes referred to as exposure or explanatory variable
What is the Dependent variable?
Affected by the independent variable
Sometimes referred to as the outcome variable
The type of data determines
- Descriptive statistics: how the data is summarised
* Inferential statistics: the statistical test used to form conclusions about the data
