Biostats introduction lecture on biostatistics for advance studies
3. Topic: Introduction to Biostatistics
Course: Biostatistics
Tahira Ashraf
(Senior Lecturer, Biostatistics)
(University of Lahore)
4. STATISTICS
Statistics is defined as:
• Study of facts and figures
• Deals with collection, organization, analysis and
interpretation of numerical data
5. Why we use Statistics
How many males and females are present here?
What is the mortality rate of Pakistan?
What is the proportion of male to female students
who failed every year in metric?
What is risk to develop Lung Cancer for those who
are smokers?
To give answers of our daily lives problems
7. DEFINITION
• It is the branch of statistics that concerns
with the applications of statistical methods
to medical and biological data.
• Biostatisticians turn health data into
knowledge
8. WHY WE NEED BIOSTATISTICS
• Biostatistics is integral to the advancement of
knowledge
• Has imperative part in public health policy
making
• Important role in research related to field of
biology, health policy, clinical medicine,
health economics, genomics, proteomics, and
many others
12. WHAT BIOSTATISTICIANS DO
• Biostatisticians are the “ the specialists of data
evaluation”
• They have expertise that allows them to take
complex, mathematical findings of clinical
trials and research-related data and translate
them into valuable information that is used to
make public health decisions.
13. WHAT BIOSTATISTICIANS DO
• Designing and conducting experiments related
to health, emergency management, and safety
• Collecting and analyzing data to improve
current public health programs and identify
problems and solutions in the public health
sector
• Interpreting the results of their findings
14. WHAT BIOSTATISTICIANS DO
• Help answer pressing research questions in
medicine, biology and public health
• To make sense of different sources of variation
and rationalize this
• Make valid inferences that can be used to
solve problems in public health
16. Variables & Constants
Age
Weight
Height
Severity of Pain
Salary
Value of “g”
Value of “pai”
Variables: A characteristic that
varies from individual to
individual or subject to subject
Constants: That remains same
from person to person or place
to place
17. VARIABLE
• DEFINITION:
A characteristic or attribute that varies from
individual to individual is termed as variable.
• EXAMPLE:
Gender, Age, Severity of disease, Disease
status, BMI etc.
18. CONSTANT
• DEFINITION:
A characteristic or attribute that does not
change from individual to individual in a
particular study
• EXAMPLE:
The gender in study title “Incidence of Low
Back Pain (LBP) among female students of
UOL” will be constant
19. CHOOSE
VARIABLE VS CONSTANT
1. MATERNAL GENDER
2. NEWBORN GENDER
3. MATERNAL AGE
“ Association of maternal anemia with
preterm birth”
20. 1. GENDER
2. AGE
“ Risk factors of IHD in patients visiting OPD
of PIC Lahore”
CHOOSE
VARIABLE VS CONSTANT
23. Types of Variables in Research
Independent Variables
The variable used to describe or measure the factors
that are assumed to cause or at least to influence the problem
Example
Drug vs placebo
Gender and age
24. Types of Variables in Research
Dependent Variables
The variable that gets modified under
the influence of some other variable
(independent)
Examples
Smoking causes lung cancer
Physical inactivity causes heart problems
Exposure to radiations cause cancer
25. EXAMPLES
Smoking causes lung cancer
Physical inactivity causes heart problems
Exposure to radiations cause cancer
INDEPENDENT DEPENDENT
27. Types of Variables in Research
Confounding Variables
that effects both the independent and
dependent variables and thus confuse the
result
• Disturbs the relationship between
independent and dependent variable
• Effects the authenticity of research
• Needs to be eliminated or controlled
28. For Example
Cause Effect/ outcome
Independent variable Dependent variable
Other Factors
(Confounding Variables)
29. For Example
A relationship is shown between the low level of mother’s education and
malnutrition in under 5’s. However, family income may be related to the mother’s
education as well as to malnutrition
Mother’s Education Malnutrition
Independent variable
Dependent variable
Family Income
(Confounding Variables)