Intro to public health

What is public health

The science and art of prolonging life, preventing disease and promoting health through the organised efforts of society”

Draws on epidemiology, psychology, sociology, economics, ethics, organisational management, environmental science, nutrition, vector biology, creative arts …..

Takes a population view

What is epidemiology

The study of the distribution and determinants of disease in human populations

What are the types of risk in public health

• Individual

• Population

Define individual risk of disease

Probability that the patient will develop a disease over a defined time period

Define population risk of disease

(incidence)

The proportion of the population who newly develop the disease over a defined time period.

Define disease rates

What proportion of people in the population have, or will develop, the disease

What are the types of epidemiological rates

•Mortality Rate

•Incidence Rate

•Prevalence Rate

Define mortality rate

Number of deaths/Population at risk in a specified period of time

Define incidence rate

The incidence of a disease is the rate at which new cases occur in a population during a specified period

Incidence rate = Number of new cases in a specified period of time/population at risk

Define prevalence rate

Prevalence rate = 

Number of cases present (new and old/existing)/

Population at risk

at a given point in time (point prevalence) or over a given period of time (period prevalence) 

Prevalence rate =  Incidence * duration

What can changes in incidence tell you

•Changes and differences in incidence between groups of people tells you about changing causes of disease

•Useful to evaluate prevention and causal factors

What can changes in mortality tell you

•Changes and differences in mortality between groups of people tells you about a COMBINATION of changes in the causes (how likely people are to get the disease) and changes in the treatment (how likely people are to survive from the disease).

•Useful to evaluate healthcare