Lecture 1: Epidemiology Flashcards
What is the definition of Epidemiology?
The study of the number and patterns of occurrence of a disease, as well as possible causes and risk factors
What is the definition of Prevalence?
How many people have the disorder now
What the definition of incidence?
How many new case sin a specific period of time
What is the definition of life-time prevalence?
How common for any individual across life
What is the prevalence of SZ?
1.5-4.0%
What is the incidence of SZ?
It is difficult to estimate because the first presentation of a psychotic episode may not be SZ.
What is the life-time prevalence of SZ?
0.7/100 or < 1 %
What is the age of onset?
Late adolescence
What is the recovery rate?
Low: 10-15%
What is the prevalence of SZ worldwide?
1.5-4.0%
What were 3 statistics in 1999/2000 for SZ in Canada?
1) 300,000 Canadians hospitalized
2) $6.9 billion in health-care costs
3) 1 in 12 hospital beds (similar to heart disease and stroke)
What was the main finding of the 1999/200 study on SZ?
A strong association with homelessness and substance abuse; some association with violence
Prevalence and incidence can be affected by two things. What are those two things?
1) Culture
2) Migration
Why would culture influence prevalence and incidence of SZ? (hint: culture is different than migration)
Cultures may view symptoms of SZ differently, resulting in different rates of people seeking treatment and diagnosis.
Why would migration influence prevalence and incidence of SZ?
1) Immigrants have a 2.5x higher rate of psychotic disorders
2) May be related to stress, health risks in either home country before migration or in new country
3) Many migrants leaving or arriving in the context of war or natural disaster
Prevalence and incidence can also be affected by parental age. Provide an explanation as to why that is.
Children of very AMABS.
Increasing risk over age 25
Male sperm (germ line cells) are a common source of genetic mutations
As AMABS (and their sperm) age, mutations are more common
Pre-natal or birth complications
<20 and >35
Complications more common in younger and AFABs
Prevalence and incidence may also be affected by exposure to inflammation and infection pre-natal or in infancy. How so?
1) Children born during flu epidemics at higher risk
2) Children of AFABS known to have had a viral infection > risk
Latitude and season of birth is also a risk factor. How so?
- Some evidence that distance from the equator is related to greater risk
- People born in colder months at greater risk.
- May be related to greater risk of infections
Name 3 factors that can also affect prevalence and incidence (risk factors).
(hint: SUC)
1) SES
2) Urban environment
3) Childhood trauma
How can SES affect prevalence and incidence?
Poverty associated with increased risk
How can urban environment affect prevalence and incidence?
- In many countries, concentration of poverty in urban areas
- Social stressors
How can childhood trauma affect prevalence and incidence of SZ?
1) Childhood trauma = 2-4x increase in risk
2) People with SZ have greater incidence of serious trauma
What are the negative outcomes of SZ?
1) Frequent health problems:
2) Cardiovascular disease, stroke
obesity, diabetes
3) Substance disorders
4) Suicide
5) Violence and victimization
6) People with SZ more likely to die at a younger age
