Epidemology

Question 1

CanMEDs

Answer 1

Medical expert

Scholar, Health advocate, Leader, Collaborator, Communicator, Professional

Question 2

Epidemiology

Answer 2

study (data-driven) of the distribution (frequency, pattern) and determinants (risk factors, causes) of health related states and events in populations

Question 3

Prognosis

Answer 3

predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen or remain stable over time

Question 4

Risk factors cardiovascular disease

Answer 4

Obesity: high BMI, hypertension, diabete, cholesterol

smoking

Question 5

Risk factors

Answer 5

some are controllable: smoking, obesity

Question 6

Coronary heart disease

Answer 6

disease of the blood vessels supplying the heart muscles

Question 7

Ischemic stroke

Answer 7

disease of the blood vessels supplying the brain

Question 8

Cardiovascular disease

Answer 8

disease affecting the heart and or blood vessels

Question 9

Obesity

Answer 9

2nd leading cause of death in US
After Smoking
1 in 4 americans are obese
1 in 2 americans are overweight
Overweight: bmi > 25
Obese: bmi > 30 
Waist and hip circumference: ratio

Question 10

BMI

Answer 10

Kg/ height^2

Question 11

Prevalence

Answer 11

P
Number of cases of a disease at a certain time or period in a population
P = (n cases / n population)* 100%
Point prevalence
part of population affected by disease, eg: 65+
Period prevalence
withing a time period
(N end - N start)/2
Life-time prevalence 
during life
Absolute prevalence:
all cases out of the population

Question 12

Incidence

Answer 12

Number of new cases
Absolute incidence:
new case out of the total population
Cumulative Incidence (CI):
(number of new case in period p/population at risk)100%
period should be specified
all members should be at risk
Incidence density (ID):
(number of new case in period p/ sum person time)
Complete follow up of all population not needed
population time at risk = person time. Person time means how long you followed 1 person. Time ends if die or get disease

Clinical practice/trials mostly have closed population: no new patient and number of patient stays the same

Question 13

Cohort study

Answer 13

studying association of the exposure to something with a disease in a longitudinal sutdy
have population of people all having that characteristic and observe how many develop the study
Then, compare to a population of not exposed
2x2 table: expose yes/no, disease yes/no and do totals
Relative Risk (RR)= (exposed with disease/n exposed)/(not exposed with disease/ n not exposed)
RR says how many times your risk is higher
RR not computed if loss of follow up ! -> hazard ratio and risk ratio : same interpretation as relative risk
>1 it is a risk factor, <1 protective factor, =1 no effect

1.3 means 30% more chance

Question 14

Adjusting risk factors

Answer 14

if looking at risk factor of weight
you need to adjust for age, gender, smoking, etc
to only take weight as a risk factor into account

Particularly, we now have an aging population thus it is important to not induce a higher cancer proportion for example

year used for standardization means the age distribution of that year was used to adjust

Question 15

Difference in gender

Answer 15

Women live longer