POPHLTH 111- module 1

What does epidemiology start by doing?

Describing population (Denominator)

Denominator

Population

Numerator

Cases of disease

Frequency of disease =

N/D

Population

Group who shares one or more common feature

Health and disease

Narrow- absence of death, diesease, disability
Broad - capacity to do what matters to you

When measuring N/D, it must be what?

Over a period of time, or at a point in time

Epidemiological equation =

(N/D)/T

Pecot stands for

Population/ participants, EG & CG, outcome and time

In an ideal study, the circle, triangle and square all_____

Have the same number of participants

How to calculate EGO?

a/EG

How to calculate CGO?

b/CG

how are EGO and CGO measured?

/1000 people

A downwards time arrow suggests?

Study takes place OVERTIME

Goal of all epidemiological studies?

Calculate EGO and CGO

Cohort study

Allocated to groups by measurement, happens overtime

Observational study vs RCT

Observational is real life, RCT allocate to groups

Is death measured by incidence of prevalence?

Always incidence

Sideways arrow of time means

Measured at a point in time

Downwards time arrow means

Measured overtime

Calculating EGO and CGO incidence

add time. EGO = a/EG(/T)

Calculate EGO and CGO prevalence

T = 1 so equation is unaffected

What does it indicate if incidence changes rapidly overtime?

The disease is preventable (environmental factors often)

Numerical

Numbers

Categorical

Yes or no, often above or below certain number

Is incidence categorical or numerical?

Always categorical

Is prevalence numercial or categorical?

Both

Cross sectional study

Same as cohort study except its measured at one point in time, and so can only measure prevalence, whilst cohort measures both