Epidemiology Flashcards
Define epidemiology
The study of the distribution and determinants of health-related states and events in human populations (not individuals).
The application of this study to disease control.
What are some characteristics of epidemiological study?
data driven
systematic and unbiased approach
relies on careful observation and valid comparison between groups
draws on methods from other scientific fields
- biology
- economics
- social
- behavioural
Describe ‘distribution’.
the frequency and pattern of events
frequency:
- number of events (counts)
- number of events in comparison to the size of the population (rates)
pattern:
- time patterns e.g., annual, weekly, monthly, daily
- place patterns e.g., geographic location, urban/rural differences, work/school
- personal patterns e.g., age, gender, sexual orientation, disability
Describe ‘determinants’.
the causes or other factors that influence the occurrence of disease/other health related events.
helps to investigate the hows and whys of disease.
helps to assess the difference between different population groups and occurrence of disease.
What are the 5 different health related states/events?
communicable disease non-communicable disease birth outcomes mobidity mortality
Describe the applications of epidemiology.
Diagnosing the health of a community.
Giving practical and appropriate public health advice/interventions to control and prevent disease in the community.
What are the 3 aims of epidemiology?
- Describe the pattern, distribution and severity of disease within a community
- Understand why disease is more common in some groups than others
- provide information necessary to provide interventions to control, prevent and treat disease
Define the term ‘infection’.
infection: the replication of organisms in a host tissue, which may cause disease.
Define the term ‘infectious disease’.
Disease caused by a pathogenic organism, which can be transmitted from one infected living organism (person or animal, or contaminated object, to a susceptible host’
Define ‘non-communicable disease’.
- chronic diseases e.g. diabetes
- tend to last a long duration of time
- usually the result of multiple genetic, physiological, social and behavioural factors.
Define the term ‘sporadic disease’.
disease that occurs infrequently and sporadically.
What is the difference between endemic, epidemic, and pandemic disease?
endemic - consistently present in a certain region/population. Low spread.
epidemic - sudden increase in cases spreading through a large population/region e.g., whole country.
pandemic - sudden increase in cases spreading through multiple regions/countries/continents.
Define the term ‘mortality’.
The number of deaths in a certain group of people over a certain period of time.
Define the term ‘morbidity’.
Having the disease, or symptoms of a disease.
Also refers to the amount of disease within a population.
What are the different types of risk factors in epidemiology?
- Fixed marker
- Variable risk factor
- Variable marker
- Causal risk factor
Describe the term ‘fixed marker’.
Risk factors that cannot change e.g., sex, age, ethnicity.
Define the term ‘variable risk factor’.
A risk factor that can change spontaneously or as a result of an intervention.
Define the term ‘variable marker’.
A risk factor, that even when manipulated, doesn’t change the outcome.
Describe the term ‘rates’ and why they are usual as a measure of disease?
Rates are a measure of the number of cases in a given period of time (usually per year), compared to the size of the population being measured.
they are useful as they allow the comparison of the occurrence of disease in populations that differ in size. E.g., comparing the rates of COVID in the UK and Australia.
