HLTH 323 mod 3 Biostats 101

• statistics: the science of collecting, organizing, analyzing, interpreting, and presenting numerical data

• Biostatistics: a branch of statistics applied in many areas of biology including epidemiology, medical, and health sciences

Different Types of Variables in Biostatistics

• Independent (exposure/predictor) variable

• dependent (outcome) variable

• Others to consider:

  • mediator - explains why a relationship happens

  • moderator - modify the relationship based on exposure status

  • confounder

  • covariate 

Hypotheses

• hypothesis is a productive statement (ie. speculative proposition) for a phenomenon which is testable

  • null hypothesis H0

  • alternative hypothesis H1

  • when P < 0.05 there is significant statistical difference

Different Statistical Techniques Commonly Used in Epidemiology

Prevalence: proportion of a population with existing cases over a specific period

Incidence: measures new cases over a specific period

Correlation: a simple statistic where you can find statistical significance with any of two variables. rarely used in epidemiology

Association: based on theory or hypothesis

Interpreting Correlation Coefficients r

Interpreting Logistic Regression