7. 2. INFERENTIAL
BIOSTATISTICS.
are concerned with reaching conclusions
from incomplete information,
that is, generalizing from the specific sample.
8.
9. VARIABLE :
It is the characteristic of the
person,
object
or phenomenon
that can take on any value.
10. DATA:
It is the set of values of one or more variables
recorded on
one or more individuals.
11. Primary Data:
Census is an example of
collecting primary data from population
Secondary Data:
Already existing data about problem /
population
example from hospital record, to use the
census data.
12. TYPES OF DATA
1. QUALITATIVE DATA :
It is the data which shows individual
values falling into separate classes,
these classes may have no numerical
relationship with one another.
Example:
hair color , severity of disease.
13. QUALITATIVE DATA
A.NOMINAL B.
ORDINAL DATA
DATA ORDERED OR
CATEGORICAL
It is the data that It is the data in which
there is natural
one can name, it
ordering of the
is unordered, categories.
either-on type of Example: severity of
data. disease (Mild, Moderate,
Example: severe), occupational
groups
Sex (Male, Female)
hair color.
14. 2. QUANTITATIVE DATA :
It is the data which
shows some numerical value.
Example:
Family size , height , weight.
15. QUANTITATIVE DATA
A. DISCRETE QUANTITATIVE DATA
It is the quantitative data that takes
only integral (whole number) of
values.
Example: Number of children in
family,
Number of deaths.
B. CONTINUOUS QUANTITATIVE
DATA
It is the quantitative data that can be
recorded on continuous scale i,e it can
16. Sources of data on community health
Data may come from different sources:
Surveillance systems (e.g., NIH)
Planned surveys (Government, Universities, NGOs)
Experiments (Pharmaceutical Companies)
Health Organizations (Administrative Data sets)
Private sector (Banks, Companies, etc)
Government (All government agencies)
Census: (periodic count, after every 10 ys:)
There are 2 principal methods for
Enumeration of population.
De facto:
Which allocates persons according to their location at the time of enumeration.
and the total of all persons present at the time of the Census as the de facto
population or persons �present in the area� on Census Day
De jure:
this assigns them according to their usual place of residence
( The total of all usual residents is generally referred to as the de jure
population
17. Organizing Data
Frequency Table
Frequency Histogram
Relative Frequency Histogram
Frequency polygon
Relative Frequency polygon
Bar chart
Pie chart
stem-and-leaf display
Box Plot
18. PRESENTATION OF DATA
RATES,RATIOS AND PROPORTIONS.
FREQUENCY DISTRIBUTION TABLES:
- Simple Tables.
- Complex Tables.
- 2 x 2 Tables.
CHARTS AND GRAPHS.
19. RATE
A RATE IS DEFINED AS THE NUMBER OF
EVENTS
PER UNIT OF POP ; PARTICULAR TIME
PERIOD.
RATE= (A/A+B) x
TO CALCULATE A RATE,WE NEED THE
FOLLOWING:
1. NUMERATOR i.e. THE No: OF EVENTS
OCCURINGIN A DEFINED PERIOD.
2. DENOMINATOR i.e. THE DEFINED
POPULATION.
3. DEFINED PERIOD OF TIME
4. A MULTIPLIER.
20. A RATE MEASURES THE
OCCURANCE OF SOME
PARTICULAR EVENT IN A
SPECIFIED POPULATION IN A
DEFINED PERIOD OF TIME.
THE VARIOUS CATEGORIES OF RATE ARE:
1. CRUDE RATES
2. SPECIFIED RATES
3. STANDARDIZED RATES.
21. RATIO
A RATIO IS THE EXPRESSION OF
RELATIONSHIP BETWEEN TWO
RANDOM QUANTITIES.
IT IS OBTAINED BY DIVIDING ONE
QUANTITY BY ANOTHER.
EXAMPLE : Male : Female Ratio,
Rural: Urban Ratio,
Doctor : Patient Ratio,
RBC : WBC Ratio.
22. PROPORTION
A PROPORTION IS THE NUMERICAL
EXPRESSION OF A PART DIVIDED BY
THE WHOLE.
INA PROPORTION, THE NUMERICAL IS
THE PART OF THE DENOMINATOR.
PROPORTION = A
A + B
WHEN A PROPORTION IS MULTIPLIED
BY 100, IT IS CALLED A
PERCENTAGE.
23. Organizing Data
Frequency Table
Frequency Histogram
Relative Frequency Histogram
Frequency polygon
Relative Frequency polygon
Bar chart
Pie chart
stem-and-leaf display
Box Plot
24. Presentation of statistical Data
1.Tabulation
Simple T
Frequency distribution T
2. Charts & Diagrams
1. Bar charts
a. simple bar chart
b. Multiple bar chart
c. component bar chart
3. Histogram
Frequency polygon
Line Diagram
Scatter Diagram
3.Pie charts
4. Pictogram
5. statistical Maps
25. Tabulation
Are devices for presenting data
May be simple or complex
Some principles
Table should be numbered (Tab:1 or 2 )
Title
Headings of column & rows
Data alphabetically or geographically
Not too large
Footnotes
26. Table 1
Population of some cities of Saudi Arabia
City Population
Arar 240000
Sakaka 114000
Source: Wikipedia
27. Frequency distribution Table
Data is first split up in to convenient group (class intervals) & no: of
items ( frequency) are in adjacent columns
E.g:- 2358235789742467324679
Age group Frequency
0-4 //// //// 10
5-9 //// //// // 12
28. Charts & Diagrams
For simple statistical data
Have a powerful impact on the imagination of the people
Especially in newspapers & magazines.
Diagrams are better retained in mind than statistical
tables.
29.
30.
31. Bar charts
Way of presenting a set of numbers by the
length of a bar
length of a bar is proportional to the magnitude
to be represented.
Easy to prepare
Values to be compared
45. Shaded maps
When refer to geographic or administrative areas, according to
suitability. Presenting data of varying size
Areas are shaded with different colors
