LECTURE 4 (Epidemiology)

Question 1

Which questions does Epidemiology answer?

Answer 1

• Who?
• Where?
• When?

Question 2

Which function of Public Health is Epidemiology?

Answer 2

Assessment

Question 3

What is Epidemiology?

Answer 3

Epidemiology is the study of populations to find the causes of health and disease

[the study of the distribution and determinants of disease frequency in human populations]

Question 4

What is an Epidemic?

Answer 4

An increase in the frequency of a disease above the usual and expected rate (Endemic rate)

Question 5

What is the ultimate goal of Epidemiology?

Answer 5

To use this knowledge to control and prevent the spread of disease

Question 6

Who is the father of modern epidemiology?

Answer 6

John Snow

Question 7

What is the importance of John Snow?

Answer 7

Concerned about a CHOLERA EPIDEMIC that struck London in 1848 -> Death rates high in parts of thames polluted with sewage -> Lambeth company changed to another area of Thames -> Formulated the HYPOTHESIS that cholera was spread by polluted drinking water

Question 8

Describe the experiment that John Snow did

Answer 8

Snow tested his hypothesis in a natural experiment -> Snow went to each house in which someone had died of cholera to determine which company supplied the water -> Cholera deaths 8.5x higher in houses supplied by Southwark and Vauxhall company -> Convincing evidence that deaths from choler were linked with the source of water

Question 9

What is Epidemiological surveillance?

Answer 9

What governments require that certain notifiable diseases be reported as soon as they are diagnosed

Question 10

What is a notifiable disease?

Answer 10

A disease that the law requires to be reported to public health authorities as part of the public health surveillance system

Question 11

What must all physicians, hospitals and clinical labaratories report?

Answer 11

Any case of notifiable disease or condition to their local health department which in turn reports to the state health department and the Centers for Disease Control and Prevention (CDC)

Question 12

What is are the advantages of reporting notifiable diseases?

Answer 12

• Timely reporting of cases of notifiable diseases allows public health authorities to detect an emerging epidemic at an early stage
• Measures can be taken to control the spread of infectious diseases

Question 13

What is the importance of reporting chronic diseases?

Answer 13

It would help to identify causes of these diseases including ENVIRONMENTAL CAUSES that could be controlled or eliminated, preventing further harmful effects

Question 14

What is a chronic disease?

Answer 14

A disease that is marked by long duration or frequent recurrence, usually incurable but not immediately fatal

Question 15

List common chronic diseases

Answer 15

• Cardiovascular disease
• Cancer
• Diabetes
• Alzheimer’s disease
• Acquired immunodeficiency syndrome

Question 16

What is the main risk factor of lung cancer?

Answer 16

Smoking

Question 17

What is a risk factor?

Answer 17

A characteristic that has been demonstrated statistically to increase a person’s chance of developing a disease or being injured

Question 18

What was the first major epidemiological study of a chronic disease?

Answer 18

An Epidemiological study launched in Massachusetts in 1948

Question 19

What are the risk factors of cardiovascular disease?

Answer 19

• High BP
• High blood cholesterol
• Smoking

Question 20

How are weight and exercise connected with cardiovascular disease?

Answer 20

Weight gain and lack of exercise were found to be associated with increased blood pressure and cholesterol values and with an increased risk of heart disease

Question 21

What are the advantages of exercise?

Answer 21

• Increase HDL “good cholesterol”
• Protect against heart disease

Question 22

From which study was HDL cholesterol and LDL cholesterol identified?

Answer 22

Framingham study

Question 23

What happened in late 1950 and early 1952?

Answer 23

Two major epidemiological studies were started that convincingly established a link between lung cancer and tobacco smoking

Question 24

What were the conclusions from the lung cancer study?

Answer 24

• death rate increased as amount smoked increased
• death rate decreased as length of time since participant had quit smoking increased
• lung cancer mortality between smokers and non-smokers was the same whether in rural or urban areas (difference could not be attributed to air pollution)
• deaths from heart attacks are higher in heavy smokers than non-smokers