Epidemiology Flashcards
What is epidemiology?
- The study of populations in order to determine the frequency and distribution of disease
- (it helps in identifying risk factors for disease and determining optimal treatment approaches to clinical practice and preventative medicine)
What are the major roles of epidemiology? (7 points)
- Monitor infectious and non-infectious diseases
- Study natural history of diseases
- Investigation of disease risk factors
- Health care needs assessment
- Development of preventative programmes
- Evaluation of interventions
- Health service planning
One major role of epidemiology is to study the natural history of diseases. What are the groupings of these? (4 points)
- Self-limiting
- Chronic
- Fatal
- Unknown
One major role of epidemiology is for health needs assessment. This is what care services are required by particular groups. What is this dependent on?
- The health status and demographics of the population
One major role of epidemiology is the development of preventative programmes. What is this based on?
Knowing risk factors of diseases and attempting to prevent exposure to these factors
What are the 3 main types of epidemiological study?
- Descriptive (observational)
- Analytic (observational - case control or cohort)
- Intervention/experimental
What are 2 terms that are a measure of disease frequency?
- Prevalence
- Incidence
What is meant by the term ‘prevalence’?
- A measurement of ALL individuals affected by the disease within a particular period of time or point in time
- It is the number of existing cases in a population
- Number of affected individuals (cases) divided by the total number of persons in the population
- Prevalence estimates are obtained from cross-sectional studies or derived from registers
- It is used as an estimate of how common a condition is within a population over a certain period of time or point in time
What is meant by the term ‘incidence’?
- A measurement of the number of NEW individuals who contract a disease during a particular period of time
- Number of new cases or events during a specific period of time in a defined population
- Incidence estimates obtained from longitudinal studies or derived from registers
Why might a chronic incurable disease like diabetes have a low incidence but a high prevalence?
Because the prevalence in the cumulative sum of the past year incidence rates
Why might a short duration curable condition such as the common cold have a high incidence but a low prevalence?
Because many people get a cold each year, but few people actually have a cold at any given time (so prevalence is low)
In descriptive studies the main variables broadly fall into 3 categories. What are these categories?
- Time
- Place
- Person
OR
- Where
- When
- Who
When sampling a population for a survey, is it necessary to study the whole population to obtain valid information about that population?
- No
What are the advantages of sampling as a survey method? (4 points)
- Reduces no. of individuals to be sampled
- Reduces cost
- Higher response rate
- Higher quality of information collected
Why must a sample be representative of the population being investigated?
- As this aims to avoid bias
