PRELIM LEC 1 (1): INTRODUCTION TO BIOSTATISTICS Flashcards
INTRODUCTION TO BIOSTATISTICS
are the basic sciences of public health
Epidemiology and biostatistics
INTRODUCTION TO BIOSTATISTICS
is a branch of applied mathematics which deals with the collection, organization, presentation, analysis and interpretation of data.
Statistics
INTRODUCTION TO BIOSTATISTICS
is the application of statistics to problems in the biological sciences, health, and medicine
Biostatistics
INTRODUCTION TO BIOSTATISTICS
is the study of the distribution and determinants of health, disease, or injury in human populations and the application of this study to the control of health problems
Epidemiology
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
Generate a hypothesis
Based on scientific rationale
Based on observations or anecdotal evidence
(not scientifically tested)
Based on results of prior studies
Examples of a hypothesis
The risk of developing lung cancer remains constant
in the last five years
The use of a cell phone is associated with developing
brain tumor
Vioxx increases the risk of heart disease
Address a public health question
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
Survey study is used to estimate the extent of the disease in the population
Surveillance study is designed to monitor or detect specific diseases
Observational studies investigate association between an exposure and a disease outcome They rely on “natural” allocation of individuals to exposed or non-exposed groups
Experimental studies also investigate the association between an exposure, often therapeutic treatment, and disease outcome Individuals are “intentionally” placed into the treatment groups by the investigators
Conduct a study
is used to estimate the extent of the disease in the population
Survey study
is designed to monitor or detect specific diseases
Surveillance study
investigate association between an exposure and a disease outcome They rely on “natural” allocation of individuals to exposed or non-exposed groups
Observational studies
also investigate the association between an exposure, often therapeutic treatment, and disease outcome
Individuals are “intentionally” placed into the treatment groups by the investigators
Experimental studies
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
Numerical facts, measurements, or observations obtained from an investigation to answer a question
Influences of temporal and seasonal trends on the reliability and accuracy of data
Examples: The number of lung cancer cases from 1960–2000 in the United States
The number of deaths from cardiovascular diseases in Whites and African Americans from 2000–2004
Collect data
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
Descriptive statistical methods provide an exploratory assessment of the data from a study
Exploratory data analysis techniques
Organization and summarization of data
Tables Graphs Summary measures
Describe the observation/data
methods provide an exploratory assessment of the data from a study
Descriptive statistical
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
Inferential statistical methods provide a confirmatory data analysis Generalize conclusions from data from part of a group (sample) to the whole group (population)
Assess the strength of the evidence Make comparisons Make predictions Ask more questions; suggest future research
Assess the strength of evidence for/against a hypothesis; evaluate the data
methods provide a confirmatory data analysis
Inferential statistical
ROLE OF QUANTITATIVE METHODS IN PUBLIC HEALTH
The study results will prove or disprove the hypothesis, or sometimes fall into a grey area of “unsure”
The study results appear in a peer-review publication and/or are disseminated to the public by other means
Consequently, the policy or action can range from developing specific regulatory programs to general personal behavioral changes
Recommend interventions or preventive programs
2 TYPES OF STATISTICS
Descriptive statistics
Inferential statistics
deals with the collection and presentation of data and collection of summarizing values to describe its group characteristics
Descriptive statistics
deals with predictions and inferences based on the analysis and interpretation of the results of the information gathered by the statistician
Inferential statistics
numerical characteristics or attribute associated with the population being studied
Variables