Introduction to Biostatistics

Statistics and Biostatistics

• Statistics is the study and use of theory and methods for the analysis of data arising from random processes or phenomena.
• It involves making sense of data and provides fundamental tools and techniques of the scientific method.
• Statistics involves:
  • Forming hypotheses
  • Designing experiments and observational studies
  • Gathering data
  • Summarizing data
  • Drawing inferences from data and testing hypotheses

Divisions of Statistics

• Mathematical Statistics: studies and develops statistical theory and methods in the abstract.
• Applied Statistics: applies statistical methods to solve real problems involving randomly generated data and develops new statistical methodology motivated by real problems.

Biostatistics

• Biostatistics is the branch of applied statistics directed towards applications in the health sciences and biology.
• It involves the application of statistical methods to solve problems in health sciences and biology.

Data and Variables

• Data: observations of random variables made on the elements of a population or sample.
• Data can be quantities, numbers, or qualities, attributes measured or observed, and collected and/or analyzed.
• A collection of data is often called a data set.
• Variables:
  • Can be quantitative (measurable): heart rate, heights, weight, age, size of tumor, volume of a dose.
  • Can be qualitative (categorical): gender, race, drug name, disease status.

Populations and Samples

• A population: the collection or set of all of the values that a variable may have.
• A sample: a part of a population.