1. ALLPPT.com _ Free PowerPoint Templates, Diagrams and Charts
Biostatistics
1ST session
Prof Najlaa Fawzi
ALLPPT.com _ Free PowerPoint Templates, Diagrams and Charts

2. In physiology and anatomy
Application and Uses of Biostatistics as a Science
In physiology and anatomy
To define what is normal or healthy in a population and to
find limits of normality in variables such as weight and pulse
rate—the mean pulse rate is 72 per minute but up what limits
it may be normal.

3. In pharmacology

4. In medicine
I . To compare the efficacy of a particular drug, operation or line of treatment—for this, the percentage cured, relieved or died
II . To find an association between two attributes such as cancer
and smoking
iii. To identify signs and symptoms of a disease or syndrome

5. Common Statistical Terms
Data
Value

8. For example:
- the heights of adult males,
- the weights of preschool children,
the ages of patients seen in

9. Number of sick children admitted to hospital
Discrete : characterized by gaps or interruptions
in the value that
can assumed
(i.e. can't assume
fraction like 2.3 persons).
Discrete
variable has no unit.
Number of Children in a Family 1 2 3 4 …
Number of sick children admitted to hospital 10 15
20…
Minutes to end of Class 55 45 30 5

10. b-Continuous: not have gaps or interruption, e.g. S. cholesterol
& weight (i.e. we can say
25.8 kg in
weight).
glucose level.
Variable has unit.
Hb,

11. 2-Qualitative: that which can't be measured in
usual sense
,but we
can describe them in categories
&there is no numerical value.
e.g. eye colors ,type of anemia, blood group ,socio-
economic status

14. Independent and Dependent variable
The two main variables in an experiment are the independent
 and dependent variable.
An independent variable is the variable that is changed or
controlled in a scientific experiment to test the effects on
the dependent variable.
A dependent variable is the variable being tested and
 measured in a scientific experiment.

18. Four Levels of Measurement
Measurements and Measurement Scales
Measurement : this may be defined as the assignment of numbers
to objects or events according to a set of rules.
Four Levels of Measurement

19. 1-The Nominal Scale: the lowest measurement
scale is the nominal
scale,
as the name indicates it
consists of ''naming'' observations
or classifying
them into mutually exclusive and
collectively
categories .
Medical diagnosis
Male – female
Country of Birth
Race, Blood group

20. 2-Ordinal Scale allow us to rank order the items we measure in terms of which has less and which has more of the quality represented by the variable, but still they do not allow us to say "how much more.”
A typical example of an ordinal variable is the socioeconomic status of families.

21. Ordinal Scale data Examples
Pain level (Mild, Moderate, Severe)
Tumors (Stage 0, ……, IV)
Arthritis (Class 1, ……, 4 )
Military Rank (Lt., Capt., Maj., Col., General)

22. due to the presence of minus numbers,
3-Interval scale: each measurement is assigned to
number of categories that are equally spaced with
no true zero point,
it does not begin from zero
due to the presence of minus numbers,
e.g. temperature.
With this scale ,it is not only possible to order
measurement ,
but also the distance between any
two measurements is known ,
the difference
between measurement of 20 &
measurement of 30 is
equal to the difference between measurement
of 30 &40.

23. T he interval scale unlike the nominal and ordinal
scales is
a truly quantitative scale.

25. Frequency
Class interval 11
30 – 39 46
40 – 49 70
50 – 59 45
60 – 69 16
70 – 79 1
80 – 89
189
Total