Chapter 1: Epidemiological Context And Measures Flashcards
Define epidemiology
The study of the occurrence, distribution (frequency and pattern), determinants of disease in populations
Define descriptive epidemiology
Largely characterised health outcomes by time, place and person
Define analytical epidemiology
Analyse what determinants contribute to the development or prognosis of disease in a population
Define target population
Larger group from which a smaller study population is selected
Define population at risk
Encompasses all individuals who are susceptible to disease at the outset/ beginning of a defined period (forms the denominator). I.e. must be free of the disease at onset – if disease develops not part of population at risk.
Define point prevalence
The proportion of people in a population that have a disease at a specific point in time
Define period prevalence
The proportion of people in a population that have a disease at any time during a specified time interval or period
Define incidence
The number of new disease onsets per specified unit of population during a specified period of time
Define incidence proportion
The number of new cases within a specified time period divided by the size of the population initially at risk aka cumulative incidence
Define incidence rate
number of new disease onsets in a period/
population at risk during the same period (person time at risk)
Define person-time at risk
Period of time an individual is at risk of developing the disease of interest (forms the denominator in incidence rate) excludes death and disease development in individuals
Describe the relationship between incidence and prevalence
Key difference - disease duration
Prevalence is equal to the incidence rate multiplied by the disease duration P = ID
