Cross sectional studies

A scientific presentation about the Cross sectional studies for the researchers

1. Cross-Sectional
Studies
Dr. Faiza Abou El-Soud
Professor-Community Health Nursing
MenoufiyaUniversity-Egypt

2. ➢Define cross-sectional study design
➢Reason to use cross-sectional study design
➢Different items between cross-sectional and longitudinal study.
➢Discuss types of the cross-sectional studies
➢identify the design of a hypothetical cross-sectional study
➢Identify advantages of cross-sectional study design
➢Discuss disadvantages of cross-sectional study design

3. Classification

6. Definition Reasons to study CS

7. 1-Descriptive Cross-sectional
studies
•Information about /
variables
•Estimate problem-prevalence
•Period prevalence
•Disease & suspected risk
factors population /specfic
individuals
2-Analytical Cross-sectional
studies
•Information -presence
& stength of
•Predictors/ deteminants
of the diseases
•Testing of hypothesis
3-Both

8. I. Descrpitve Cross-sectional studies
Example : Weight of preterm babies in the 1st week in the incubator
Example : Gender (male and female), Smoking condition...

9. II. Analytical Cross-sectional studies
•Information -presence & stength of
•Predictors/ of the diseases.
•Testing of hypothesis :
✓First method
✓Second method

10. hypothetical
There are2 methods:
First method:
Identification of four subgroups based on presence orabsence of and
presence or absence of.

11. hypothetical
Second method:
Two possible approaches to the analysis of results:
(A) the Rate of the Proportion of the Persons with Disease
Calculate the prevalence of
the prevalence of . Or
(B) the Rate of the Proportion of the Persons with Exposure
Calculate the prevalence of
compared to the prevalence of .

12. The Rate ratiois the rate
of the of the
over the
•The Rate ratio
to measure an
of the
disease with exposure

13. Second method: Design of a hypothetical cross-sectional study: A 2 ×2 table of the
findings from the study

14. :

15. :

16. :

17. : Interpretation
the rate ratio of 1.0indicates equalrates in the
two groups,
the rate ratio greater than 1.0indicates an
increasedrisk for the exposed group ,
the rate ratio less than 1.0indicates a decreased
risk for the exposed group.

18. •Interpretation : People who are exposed to smoking had 6.0 timesas
likely to develop hypertension as those who are not
exposed.
•Risk of hypertension among smokers patients= 120/400 = 0.3 = 30%
•Risk of hypertension among non-smokers patients= 30/600 = 0.05= 5%
•Risk ratio =0.3 ⁄ 0.05 = 6
•The risk ratiois more than 1.0, indicating a incresaed risk or protective
effect for the exposed (smokers) patients. The risk ratio of 6 indicates
that smokers patients were likely (60%, actually) to develop
hypertension compare to nonsmokers patients.
: Interpretation

19. Home Task :
Estimate the Risk Ratiofor this example and give your
interpretation?

22. Thank You