P1. Nature of Biostatistics and Data Processing Flashcards
Science dealing with the collection, organization, analysis, and interpretation of numerical data.
COAI
Statistics
Art of summarizing data so that non-statistician can understand it.
Statistics
- tool in decision making
- formulation of good judgement
- METHOD or DATA
Statistics
BIO means?
STATISTICS means?
LIFE
DATA
a special branch of statistics which deals with quantitative and qualitative aspects of vital phenomena
Biostatistics
data required in the planning, administration, and evolution of health programs
Health Statistics
2 Branches of Statistics?
- Descriptive Statistics
- Inferential Statistics
- summarize and present data
- measures of central tendency & variability
- tabulation & graphical presentation
- understanding, analysis and interpretation of data
Descriptive Statistics
- conclusions & generalizations about target population 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
Parameter
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
Types of Data according to Source:
Primary Data
Secondary Data
Types of Variables:
1. descriptions or labels to distinguish one group from another
2. can be measured and ordered according to quantity or amount and expressed numerically
- qualitative
- quantitative
Types of Quantitative Data:
1. can assume a finite or countable number of values.
2. can assume an infinity or other possible values
- discrete
- continuous
Scale of Measurement of Variables:
- Nominal
- Ordinal
- Interval
- Ratio
- names or identifiers of a category
- Always qualitative
- Does not represent any amount or quantity
Nominal
- 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
Biostatistics Flowchart?
- Data Collection
- Data Processing (coding, encoding, editing)
- Analysis
Conversion of verbal/written information into numbers which can be more easily encoded, counted and tabulated.
Data Coding
4 types of codes:
- field code
- bracket code
- factual code
- pattern code
actual value or information given by the respondent
Field Code
recorded as range of values rather than actual values
Bracket Code
codes are 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
Coding Problems
- No response
- Not applicable questions
A 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
id
- Enter as is (number must be unique)
Identification number
com
- 1 = ?
- 2 = ?
Type of community
- 1 = rural
- 2 = urban
name
- Enter as is
Name of respondent
sex
- 1 = ?
- 2 = ?
- 9 = ?
Gender of respondent
- 1 = male
- 2 = female
- 9 = no asnwer
age
- Enter as is
- 9 – no answer
Age in years
occ
- 1 = ?
- 2 = ?
- 3 = ?
- 9 = no asnwer
Occupation of respondent
- 1 = white collar
- 2 = blue collar
- 3 = none
fhpn
- 1 = ?
- 2 = ?
- 7 = ?
- 9 = no asnwer
Family history of HPN
- 1 = with
- 2 = without
- 7 = i don’t know
Entering the data/responses in a spreadsheet
– MS Excel
– MS Access
– Epi Info
Data Encoding
Inspection and correction of any errors or inconsistencies in the information collected
must be done (?) during data collection, encoding, before data analysis
Data Editing
2 types of Editing?
- Field Editing
- Central Editing
- 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
