Health education has been defined differently: National Conference on Preventive Medicine in 1975 defined it as "a process that informs, motivates, and helps people to adopt and maintain healthy practices and lifestyles, advocates environmental changes as needed to facilitate this goal, and conducts professional training and research to the same end."[4] The Joint Committee on Health Education and Promotion Terminology of 2001 defined Health Education as "any combination of planned learning experiences based on sound theories that provide individuals, groups, and communities the opportunity to acquire information and the skills needed to make quality health decisions."[5] The World Health Organization (WHO) defined Health Education as consisting of "consciously constructed opportunities for learning involving some form of communication designed to improve health literacy, including improving knowledge, and developing life skills which are conducive to individual and communitythe United States, around forty states require the teaching of health education. A comprehensive health education curriculum consists of planned learning experiences that will help students achieve desirable attitudes and practices related to critical health issues. Studies have shown that students are able to identify how emotions and healthy eating habits can possibly impact each other.[20] Some of these are: emotional health and a positive self-image; appreciation, respect for, and care of the human body and its vital organs; physical fitness; health issues of alcohol, tobacco, drug use, and substance use disorders; health misconceptions and myths; effects of exercise on the body systems and on general well being; nutrition and weight control; sexual relationships and sexuality, the scientific, social, and economic aspects of community and ecological health; communicable and degenerative diseases including sexually transmitted diseases; disaster preparedness; safety and driver education; factors in the environment and how those factors affect an individual's or population's environmental health (ex: air quality, water quality, food sanitation); life skills; choosing professional medical and health services; and choices of health careers.are written expectations for what the students should know and be able to do by grades 2, 5, 8, and 12 to promote personal, family, and community health. The standards provide a framework for curriculum development and selection, instruction, and student assessment in health education. The performance indicators articulate specifically what students should know or be able to do in support of each standard by the conclusion of each of the following grade spans: Pre-K–Grade 12. The performance indicators serve as a blueprint for organizing student assessment.[

1. CROSS SECTIONAL STUDY
Presentor-Dr PRAVEEN MURUGESAN ,first year PG
GUIDE -Dr KRISHNA PRASANTH , Assistant professor ,SBMCH

2. EPIDEMIOLOGY DEFINITION
•Epidemiology is the study of occurrence and the distribution of
health-related states or events in specified populations, including the
study of determinants influencing such process and the application
of this knowledge to the control relevant health problem.
(PARK textbook 26 th edition)

3. DESCRIPTIVE ANALYTICAL
CASE
RESPORTS
CASE
SERIES
DESCRIPTIVE
SURVEYS
OBSERVATIONA
L
EXPERIMENTAL
CROSS
SECTIONAL
CASE
CONTROL
COHORT
LAB TRIALS FEILD
TRIALS

4. CROSS SECTIONAL STUDY
• Cross sectional study is a "SNAPSHOT "of a population at a single
point in a time.
• Also called “prevalence studies “
• Determines the ‘burden of disease’in a population
• Exposure and outcome determined simultaneously

6. TYPES OF CROSS SECTIONAL STUDY
Descriptive
To describe the characteristics of a
population.
Examining the dietary habits of high
school students.
Analytical
To investigate associations between
variables.
Studying the correlation between
smoking and lung disease in adults.

7. Steps in conducting a cross-
sectional study
1)Objective of the study should be specified.
2)Population must be defined.
3)Defining the disease under study.
4) Describing the disease, its risk factors and identifying reference population
5)Measurements of disease.
6)Comparing with known indices.
7)Formulation of hypothesis.

8. • OBJECTIVE OF THE STUDY
The objectives of the study MUST be clearly stated, in measurable terms.
Each objective must be examined to ensure that it is achievable in the given
resources of time, place, person and money.

9. •POPULATION MUST BE DEFINED
Defined population can be whole population of a
geographic area or more often a representative sample
taken from it.
Example: hypertension: A person is diagnosed with
hypertension if he/she as a blood pressure of >140/90 mm
hg in two or more occasions or if he/she is a previously
diagnosed case of hypertension and is on medications.

10. •DEFINING DISEASE UNDER STUDY
For example- tonsillitis might be defined clinically as an inflammation of the
tonsil caused by infection ,usually with streptococcus pyogenes.
But this cannot be used to measure the disease in the community.
On the other hand a operational definition , such criteria would include
The presence of enlarged ,red,tonsil with white exudate ,which on throat swab
culture grow predominantly S.PYOGENES.

11.  Describing the disease in terms of time, place & person and identifying those
characteristics associated with presence or absence of disease in individuals.
 The reference population has to defined demographically.
4) Describing the disease, its risk factors and identifying
reference population

12. Example: In a study of hypertension we can also collect data during the
survey about age, sex, physical exercise, body weight ,salt intake and other
variables of interest.
Inclusion criteria: Are the characteristics that the prospective subjects must
have if they are included in the study
Exclusion criteria: Are those characteristics that disqualify prospective
subjects from inclusion in the study
MEASUREMENT OF DISEASE

13. •FORMULATION OF HYPOTHESIS
1.The population –the characteristics of the person to whom the hypothesis
applies,
2.The specific cause being considered,
3.The expected outcome-the disease,
4.The dose response relationship,
5.The time response relationship.

14. For example: “cigarette smoking causes lung cancer.” is the
incomplete hypothesis.
An improved formulation:
“Smoking of 30-40 cigarettes per day causes lung cancer in 10%of
smokers after 20 years of exposure.”

16. 16
Example of a cross section study
• Knowledge, attitude, and health seeking behavior on
leprosy among urban adults in Kancheepuram district of
Tamil Nadu: A Community-based cross-sectional study

17. Association of Socio demographic factors and knowledge
on leprosy
Variable Adequate
knowledge
n=350
Inadequate
knowledge
n= 290
OR 95% CI Chi p value
square
n % n %
Sex
Male 191 60 128 40 1.5 1.11-2.07 6.49 0.01*
Female 159 50 162 50
Education
Complete
d
schooling
136 74 49 26 3.1 2.14-4.54 36.1 0.001*
Not
Complete
d
214 47 241 53

18. Interpretation
❖ There is a statistically significant association between gender
and knowledge of leprosy.
❖ There is a statistically significant association between
completed years of schooling and knowledge of leprosy.
❖ The odds of knowledge of leprosy was 1.5 times more among
males when compared to females.
❖ The odds of knowledge of leprosy was 3.1 times higher among
participants who have completed their schooling than who have
not completed.

19. Association of Socio demographic factors and knowledge
on leprosy
Variable Adequ
ate
knowl
edge
n=350
Inadequ
ate
knowled
ge
n= 290
OR 95% CI Chi square p value
n % n %
Occupation
Prof/skilled/
semiskilled
221 59 152 41 1.5 1.13-2.13 7.07 0.007*
Unskilled/
unemployed
129 48 138 52
Marital status
Single 74 67 36 33 1.89 1.22-2.91 7.88 0.005*
Married/
divorced/
Widowed
276 52 254 48

20. Interpretation
❖ There is statiscally significant association between knowledge
on leprosy and occupation
❖ There is statistical significant association between knowledge on
leprosy and marital status.
❖ The odds of knowledge on leprosy was 1.5 times high among
employed when compared to unemployed.
❖ The odds of knowledge on leprosy was 1.89 times higher among
participants who are single than married.

23. •In this hypothetical example,the prevalence of headache in
Mobile phone users was 2.57×higher than the prevalence of
headache among nonmobile users.ofcourse this doesnot mean
that the mobile phones caused the increase in headaches as
mobile phone users might differ from nonusers in otherways.

24. Advantages of cross sectional study

25. LIMITATION OF CROSS SECTIONAL STUDY
• There is no temporality
• Measures prevalence only not incidence
• Rare disease ,condition with high fatality are not detected

26. • Generalisability limited by sampled population and limitation
• Sample size requirement may be very large.

27. Application of cross sectional studies
• They are usually conducted to estimate the prevalence of the
outcome of interest for a given population, commonly for the
purpose of public health planning.
• Appropriate for screening hypotheses because they require relatively
shorter time and fewer resources.

28. Cross sectional study application
• Cross sectional studies are widely used in palliative care research.
• Also used to understand the prevalence of various conditions,
treatment, services or other outcomes and the factors associated
with such outcomes

29. Conclusion
• ❖ Cross-sectional studies are relatively cheap observational studies and can be
conducted in a short time.
• ❖ They can be used for public health planning, understanding disease etiology
and for the formulation of hypotheses.
• ❖ They cannot be used to establish causal relationship between exposure and
outcomes.
❖ Can only be used to find the prevalence and not incidence.

30. References
• K Park. Principles of Epidemiology and Epidemiologic methods. In:
Park’s Textbook of Preventive and Social Medicine; 26th edn.
Jabalpur; M/s Banarsidas Bhanot Publisher.
• Gordis Leon, Textbook of epidemiology. 6th edition.
• IAPSM’s Textbook of Community medicine,2nd edition.
• Oxford Handbook of epidemiology for clinicians,1st edition

31. THANKS