Epidemiological Parameters

Epidemiology

Study of how disease is distributed in populations and the factors that influence or determine this distribution.

Prevalence

Proportion of individuals in a population who have a disease at a specific time.

Prevalence

Formula: # of existing cases/ Total population x 100

Incidence

Number of new cases of a disease during a specific time period.

Incidence

New cases during period/ Population at risk x 100

Attack Rate

• Used during outbreak

Attack Rate

Formula: # of new cases / Population at risk x 100

Mortality Rate

• Frequencey of occurence of death in population during a time period.

Mortality Rate

Formula: # of deaths / Total population x 1000

CFR

Proportions of individuals diagnosed with disease who die from it.

CFR

Formula: # of deaths from disease / # of diagnosed cases x 100

CBR

Births per 1,000 people pe year

CBR

Formula: # of births / mid-year population x 1000

IMR

Deaths of infants under 1 year per 1,000 live births

IMR

Formula: Infant deaths / Live births x 1000

Morbidity Rate

Incidence or Prevalence of a disease

Proportional Mortality Ratio

Proportion of all deaths due to a specific cause

PMR

Formula: Deaths from a specific cause / Total deaths x 100

YPLL

• Estimate average years of a person would have lived if not for premature death.

• Used for prioritizing health issues