4. Epidemiology

Question 1

What is the purpose of epidemiology?

Answer 1

To understand causes of health problems and to make changes that decrease risk and improve health

Question 2

What is epidemiology?

Answer 2

Understanding the distribution and determinants of disease frequency.

Question 3

How can we use epidemiology?

Answer 3

To plan and evaluate strategies. Used to better services by finding links.
E.g. First degree relative with glaucoma

Question 4

What is endemic?

Answer 4

The presence of a disease within a given geographic area. Always present at the same level. E.g chicken pox

Question 5

What is epidemic?

Answer 5

A group of illness of similar natures or an illness within a community that is in excess of normal expectancy and derived from a common source, e.g. flu, cholera.

Question 6

What is pandemic?

Answer 6

A worldwide epidemic e.g COVID 19

Question 7

What is sporadic?

Answer 7

Occasionally occuring disease/illness in population.
E.g. Tetanus

Question 8

Give examples of host factors

Answer 8

1. Sex
2. Age
3. Race
4. Occupation
5. Nutrition
6. Genetics
7. Marital status
8. Socioeconomic status
9. Religious/social customs
10. Immunisation history
11. Previous history of disease

Question 9

Give examples of environmental factors

Answer 9

1. Temperature
2. Humidity
3. Altitude
4. Water
5. Radiation
6. Pollution
7. Housing conditions
8. Food

Question 10

Give optom related examples of epidemiological factors

Answer 10

Vit A deficiency = Nutrition
Vit B deficiency = Nutrition + Sunlight
AMD = Race, age, UV
Glaucoma = ethnicity, genetics
Microbial keratitis = CL wear, cleanliness
Uveitis = systemic disease (disease affecting more than one area of the body)
Toxoplasmosis = Immunisation, undercooked food

Question 11

Give examples of inherent risk factors

Answer 11

Age
DNA
Race

Question 12

Give examples of acquired risk factors

Answer 12

Smoking
Obesity
Exposure to hazardous materials (UV)

Question 13

What is incidence rate?

Answer 13

The new cases of a disease during a set time period

Question 14

What is prevalence rates?

Answer 14

All the cases of a disease that are present at one point in time

Question 15

How are the stats presented?

Answer 15

Number affected:Total number studies

(info expressed as ratio)

Question 16

What is incidence rate used for?

Answer 16

1. Measure growth of disease
2. New infections per annum

Question 17

What is prevalence rate used for?

Answer 17

1. Measures size of an epidemic
2. Ratio of all those affected to the total population at a given time.

Question 18

Why should you be careful when looking at prevalence?

Answer 18

Is influenced by survival time after infection.
This means that:

A fall in prevalence could be due to an increase in number of deaths.

A increase in prevalence could be due to improvements in treatments OR fewer people dying from war/famine, OR more people with the disease are immigrating.

Question 19

When is incidence info more useful?

Answer 19

When there is a new disease, infectious disease to figure out who and where the disease came from to put a stop to it. (Acute disease (rapid))

Question 20

When is prevalence info more useful?

Answer 20

When all cases need to be taken into account to come up with a plan for public service.
E.g. plan for medicines number of appointments, number of optometrists needed. (Chronic diseases (worsen overtime))

Question 21

When do optoms begin intervention?

Answer 21

Ideally early.