Epidemiological studies - observational studies

Question 1

What are
observational
studies? (OS)

Answer 1

Observational studies do not involve any intervention and things are taking their natural course.
Changes of one characteristic are studied in relation to other.

Question 2

Observational

studies can be

Answer 2

descriptive or analytical.

Question 3

what do OS investigate?

Answer 3

investigate
- the occurrence and distribution of diseases

-provide useful information that may help and initiate
further research into the problem.

Question 4

what are descriptive studies?

Answer 4

NO control or comparison group

Question 5

what are analytical studies?

Answer 5

control or comparison group

Question 6

descriptive studies include

Answer 6

1. case report

2. case study

Question 7

case report

Answer 7

detailed description of of a single or several cases

Question 8

advantages of case report

Answer 8

The only way for describing and publishing rare diseases and syndromes OR unusual course of a common disease - Sources of hypotheses about aetiology, treatment and resolution of diseases that can be later evaluated by more complex epidemiologic studies - Provide very detailed and important information about the diseases pathogenesis, development and treatment - Serve as a bridge between laboratory and clinical research

Question 9

disadvantages of case report

Answer 9

Highly susceptible to bias because of the small number of cases, especially when case reports comment treatment issues or survival. - Cannot be directly transferred to clinical practice because of the great level of uncertainty

Question 10

what is a case series

Answer 10

a study of a larger group of patients with a single disease. It is a descriptive study usually with no control or comparison group. Case series describe the clinical development and treatment of a group, gathered usually at one point of time.

Question 11

example for case control study

Answer 11

framingham heart study

Question 12

objective for FHS

Answer 12

identify the common factors or characteristics that contribute to
cardio-vascular diseases (CVD) by following its development
over a long period of time in a large group of participants who
had not yet developed overt symptoms of CVD or suffered a
heart attack or stroke

Question 13

what happened in the FHS

Answer 13

careful monitoring of the
Framingham Study sample has led to the identification of the
major CVD risk factors - high blood pressure, high blood
cholesterol, smoking, obesity, diabetes, and physical inactivity
- as well as a great deal of valuable information on the effects
of related factors such as blood triglyceride and HDL
cholesterol levels, age, gender, and psychosocial issues.