Classes 3-7 Descriptive Epi And Measures Of Disease Frequency Flashcards
What is a passive surveillance system?
A system that relies on healthcare system to follow regulations on required reportable diseases/conditions. Passively waits for reports to come in to track disease frequency/occurrence over time and within populations.
What is an active surveillance system?
Public health officials go into communities to search for new diseases/condition cases
What is a syndromic surveillance system?
A system that looks for pre-defined signs/symptoms of patients related to track able-but-rare diseases/conditions
What is an epidemic?
Occurrence of disease clearly in excess of normal expectancy.
- Community/period clearly defined
- Goal is to capture disease as early as possible
What is an outbreak?
An epidemic limited to a localized increase in the occurrence of disease
- Sometimes called a “cluster”
Define Endemic
The constant presence of a disease within a given area or population in excess of normal levels in other areas
What is an emergency of international concern?
An epidemic that alerts the world to the need for high vigilance (pre-pandemic labeling)
What is a pandemic?
An epidemic spread world wide
- multi national/multi continent
What is a ratio?
A division of 2 unrelated numbers
What is a proportion?
Division of 2 related numbers
What is a rate?
A proportion (%) with time incorporated in the denominator
Differentiate between incidence and prevalence
Incidence only includes new cases of disease
Prevalence includes existing and new cases
What is the calculation for finding incidence?
of new cases of illness/# of people at risk for illness
What is the most important thing to remember when calculating incidence?
To subtract out from the starting population people who already have the disease or are immune to the disease
How do you measure incidence rate?
of new cases of disease/person time at risk for the disease
How do you calculate incidence density?
of new cases of disease/total person time of population at risk for disease
How do you measure prevalence?
of existing cases of disease/# of persons in population
Describe the difference between point prevalence and period prevalence.
Point prevalence is at a given point in time, period prevalence is prevalence over a given period of time.
How do you calculate crude morbidity rate?
of persons with disease/# of persons in a population
How do you calculate crude mortality rate?
of people who died/# of people in the population
How do you calculate cause specific morbidity rate?
of people with a specific disease/# of people in the population
How do you calculate cause-specific mortality rate?
of people who died from a specific disease/# of people in the population
How do you calculate case-fatality rate
of cause specific deaths/# of cases of disease
How do you calculate proportional mortality rate (PMR)
of cause specific deaths/total # of deaths in population
