NATURE OF BIOSTATISTICS Flashcards
- It is a science dealing with the collection, organization, analysis, and interpretation of
numerical data. - It is an art of summarizing data so that non-statistician can understand it.
- It is a tool in decision making to formulate good judgment.
- It can mean a METHOD or DATA.
Statistics
- Data reduction technique
- Tool for analyzing research projects and clinical trials
- Tool for objective appraisal and evaluation of programs
- Tool in decision making process and policy making
Uses of Statistics
Biostatistics
BIO means life.
* STATISTICS means data.
* It is a special branch of statistics which deals with quantitative and qualitative aspects of
vital phenomena
data required in the planning, administration, and evolution of health
programs
Health Statistics
distribution & determinants of health-related states and events
epidemiology
study of human population
study of human population
functioning of health care system and health affecting behaviors
health economics
heredity, genes and functions
genetics and genomics
Branches of Statistics
- Descriptive Statistics
- Inferential Statistics
Methods of summarizing and presenting data
Computation of measures of central tendency and variability
Tabulation and graphical presentation
Facilitate understanding, analysis, and interpretation of data
Descriptive Statistics
Methods of arriving at conclusions and generalizations about a target population based on
information from a sample
Estimation of parameters and hypotheses testing
Inferential Statistics
all members of a specified group
Population
subset of a population
Sample
measure of a characteristic of a population
measure of a characteristic of a population
value of a characteristic that remains the same from person to person, from time to time or from place to place
Constant
characteristics takes on different values
Variable
- According to Source
Primary Data
Secondary Data - According to Functional Relationship
Primary Data
Secondary Data
Type of Data
descriptions or labels to distinguish one group from another
Qualitative
can be measured and ordered according to quantity or amount and expressed numerically
Quantitative
assume a finite or countable number of values
Discrete
infinity or other possible values
Continuous
Simply used as names or identifiers of a category
Always qualitative
Does not represent any amount or quantity
Nominal
Simply used as names or identifiers of a category
Always qualitative
Does not represent any amount or quantity
Nominal
Represents an ordered series of relationships
May be qualitative or quantitative
Ordinal
Does not have a true-zero value starting point
Always quantitative
Interval
Modified interval level which includes zero as a starting point
Always quantitative
Ratio
systematic procedure to ensure that the information/data gathered are complete, consistent
and suitable for analysis.
Data Processing
- CODING
- ENCODING
- EDITING
DATA PROCESSING
conversion of verbal/written information into numbers which can be more easily encoded,
counted and tabulated.
data coding
actual value or information given by the respondent
Field Code
recorded as range of values rather than actual values
Bracket Code
assigned to a list of categories of a given variable
Factual Code
applicable for questions with multiple responses
Pattern Code
Rules in Code Construction
Number of rules must be kept to minimum (<8)
Codes should be exhaustive and mutually exclusive
Adopt coding convention for questions with similar answers
No response
Not applicable questions
Coding Problems
document which contains a record of all codes assigned to the responses to all questions
in the data collection form
Coding Manual
document which contains a record of all codes assigned to the responses to all questions
in the data collection form
Coding Manual
Minimum information that must be included in a coding manual
Variable name
Variable description
Coding instructions
Entering the data/responses in a spreadsheet
MS Excel
MS Access
Epi Inf
Data Encoding
Inspection and correction of any errors or inconsistencies in the information collected
During data collection, encoding, before data analysis
Data Encoding
Reviewing the accomplished data collection forms
Decoding of abbreviations or special symbols
Making callbacks/messages for verification/clarification of incomplete answers
Field Editing
Checking of inconsistencies and incorrect entries after receiving the questionnaire from the
field
Checking of encoded data
. Central Editing
Make corrections as early as possible
Reduce non-response or incomplete answers
Eliminate inconsistencies, incorrect info.
Make the entries clear, legible and comprehensive
Prepare data for analysis
Importance of Data Editing
Check for duplicate entries
Check the totals of each variable if the same as with the sample size
For qualitative data, check if categories are consistent with what is specified in the coding
manual
For quantitative data, check the minimum and maximum if they are logical given the
possible values of variable
What to check when editing data?
