class 4 Principles of Epidemiology Flashcards
what is epidemiology
The study of the distribution and determinants of health-related states and events in specified populations, and the application of this study to the control of health problems对特定人群中与健康有关的状态和事件的分布和决定因素的研究，并将此研究应用于健康问题的控制
what is the distribution of epidemiology?
WHO is affected, WHERE, and WHEN? What are the trends
or patterns of disease among groups of people
what are the determinants of epidemiology?
Causes and factors that affect the risk of disease
Infectious diseases have a single, necessary cause
Other conditions have multiple determinants
Host factors (age, nutritional status, etc.)
Environmental factors (e.g., living conditions)
how is epidemiology used?
past:To investigate, control, and prevent epidemics of infectious diseases
present: To study injuries (home / work) and chronic
disease
how could epidemiology investigate the causes of diseases?
An epidemiologist
1. counts cases and measures the population in which they arise
2. calculates rates of occurrence of a health problem and compares the rates in different groups of people
what are the uses of rate of diesases?
Differences in rates of disease in populations are used to formulate
hypotheses about the cause of a health problem or to assess exposure to a specific agent
epidemiology and community’s health status
Epidemiology is used to determine whether a community’s overall health is getting better or worse: Compares current rate to previous year/decade or to
provincial/national average
Potential health problems can also be identified (e.g., AIDS
what is rate?
rate is the frequency with which an event occurs in a defined population
what is risk?
risk is the likelihood that people without the disease but exposed to certain risk factors will acquire the disease at some point in their lives
what are risk factors?
inherited
found in physical environments
from social environments
behavioural
what is the relationship between rates and risks?
Different rates of exposure to a risk factor allow basic comparisons of
disease rates among individuals
what is RR?
Relative Risk, is the Comparison of the risk of some health-related event (e.g., disease or death) in
two groups differentiated by gender / age / exposure
what it stands for if RR>1
ppl exposed to the factor have increased risk of the outcome
what is it stands for if RR<1
exposed to the factor have decreased risk of outcome
what is prevalence
The proportion of a group possessing a disease or condition at a specific time, it includes both new and existing cases
how is prevalence measured?
measured by a single examination or survey of a group,
#of cases/# of persons
what is incidence?
发生率, The proportion of a group initially free of a
disease or condition who develop the disease or condition over a period of time
what is incidence for
incidence describes how quickly the disease occurs in the population
what is the bathtub analogy?
This analogy helps explain the concept of herd immunity and the impact of interventions on disease spread. Public health measures aim to control the flow of water into the bathtub by reducing transmission (turning down the faucet) and increasing the rate of recovery or immunity (speeding up the drain).
what is nutritional epidemiology?
Monitor and describe the food consumption, nutrient intake, and nutritional status of populations or subgroups of populations
one example of the application of nutritional epidemiology
monitor nutrition and health status of a high-risk group of individuals for several months/years
nutritional epidemiology, the past and today
past: focus on nutritient deficiencies
today: focus on chronic diseases
