BIOL 437 Week One Part 1 Flashcards
what is epidemiology?
- the study of what happens to populations
- exact definition has changed over time
- population level vs. individual level evaluation
- distribution, determinants, health-related events, specified populations
epidemic or outbreak
-disease occurrence among a population that is in excess of what is expected in a given TIME and PLACE
cluster
-group of cases in a specific time and place that might be more than expected
endemic
- disease or condition present among a population at all times
- ex. influenza
pandemic
- a disease or condition that spreads across extensive regions (countries or continents)
- ex. covid-19
rate
- number of cases occurring during a specific period
- always dependent on the size of the population during that period
distribution
- Frequency
2. Pattern
frequency
- number of cases of a specific disease
- relationship of number of cases to population size
patterns
- Time
- Person
- Place
time
- seasonal
- weekly
- daily
- hourly
place
- geographic variation
- rural vs. urban
- worksite and school locations
personal
-demographic factors relating to risk of injury or illness or disability
>age, gender, marital status, socio-economic status, behaviour, environmental exposure
determinants
-causes and other factors affecting the occurrence of disease and health related events
1. Analytic epidemiology
2. Epidemiological studies
>answer how and why
>evaluate how groups with different rates of disease differ (looking for risk factors)
health-related states or events
- originally focused only on epidemics of communicable disease
- now non-communicable also (ex. cancers)
- epidemiological methods now applied to any health-related state or event
sub-disciplines
- infectious
- chronic
- maternal and child health
- injury
- birth defects
- environmental
- occupational
- nutrition
- genetic markers
- health policy
- health behaviour
who is the ‘patient’
- epidemiologist: community
- physician: the individual
epidemiologist
- strives to identify source of exposure causing illness
- determine the potential for further spread
- determine interventions to prevent more cases or recurrences
application
- use descriptive and analytical epidemiological methods
- use experience
- use epidemiological judgement
- use of understanding of local conditions
- diagnose health of a community
- propose practical public health interventions
additional characteristics of epidemiology
- data driven
- systematic and unbiased approach
- observation and valid comparison groups
- use methods from other areas
- identifies risk factors
- identifies targets for preventive health care
what are risk factors?
- a behaviour, environmental exposure or inherent human characteristic that is associated with an important health condition
- condition with increased probability
basic sciences of public health
- Quantitative
- Casual reasoning
- Provides basic for directing practical and appropriate public health action
what do epidemiologists do?
- identify risk factors
- describe natural history of disease
- provide public health planning
- act as a resource person
- monitor disease
- communicable information
early epidemics
- greatly feared
- considered to be caused by metaphysical explanations or God’s will
- emphasis on establishing a more systematic way to explain disease
beginning of epidemiology
- empirical, observational studies
- focused primarily on infectious diseases only
sign
- something you can measure
- objective
symptom
- subjective measure
- ex. headache
epidemiology now
- integral part of clinical science
- key component of the science of public health
epidemiologic transition
-describes changing patterns of: >population age distributions >mortality >fertility >life expectancy >causes of death
4 major epidemiological transitions since beginning of agriculture
- Emergence of infectious disease and diseases related to nutrition
- Change from major epidemics to endemic disease
- Change in disease patterns from infectious to chronic to degenerative
- New diseases and re-emergence of infectious ones and rapid spread
emergence of diseases
-10,000 years ago animals were domesticated and food was produced
>nutritional deficiencies, zoonoses and increased contact with disease vectors
zoonoses
-transmission from one species to another
major epidemics to endemic disease
- human immune systems and pathogens evolved
- physical and genetic changes minimized disease effects
infectious to chronic to degenerative
- improved nutrition, clinical medicine, and public health
- cancer and CVD emerge (longer lifespan, sedentary)
- particularly in the developed world
new diseases and re-emergence
- increased globalization
eg. Sars, Zika, Ebola, covid-19
