Define epidemiology
Study of the distribution and determinants of health and disease in human populations to enable health services to be planned rationally, disease surveillance to be carried out, and preventive and control programs to be implemented and evaluated.
What is incidence a measure of?
Risk
When are crude rates not enough?
For comparing rates across populations
Name the vital events
1. Identify cause of disease and relevant risk factors
2. Determine extent of disease in community
3. Study natural history and progression of disease
4. Evaluate new and existing preventive and therapeutic measures and modes of healthcare delivery
5. Provide foundation for developing public policy relating to environmental problems, genetic issues, and other considerations regarding disease
What is prevalence a measure of?
Disease burden
What is the single most important predictor of mortality?
Name the four types of surveillance (and give an example)
Mass screening
Selective screening
Multiphasic screening
Case finding
What are the stages of the natural progression of disease (for individuals and populations)?
Individuals
1. Healthy
2. Unaware of point in time when disease begins
3. Symptoms develop, patient seeks medical care
4. Diagnosis is made, treatment begins
5. Cure, control of disease, disability, death
Population
1. Total population
2. Sick
3. Seeks care
4. HospitalizedWhat is the difference between point and period prevalence?
What are two important uses of mortality data?
Compare two or more populations
Compare population in different time periods
What type of surveillance (active vs passive) is more effective generally and why?
Active is more effective due to resource allocation
What are primary, secondary, and tertiary prevention and give an example of each
Primary prevention: action taken to prevent the development of a disease in a person who is well and does not yet have the disease in question
Secondary prevention: Identifying people in whom disease process has already begun but who have not yet developed clinical signs and symptoms of illness
Tertiary prevention: Preventing complications in those who have already developed signs and symptoms of an illness and have been diagnosed (people who are in the clinical phase)
Is proportionate mortality a measure of risk?
no
When do you use direct vs indirect adjustment?
Use direct adjustment only when you have strata-specific rates for the target population
What are the steps of the epidemiologic approach?
1. Determine whether an association exists between exposure to a factor and the development of a disease
2. Derive appropriate inferences about a possible causal relationship from the patterns of associations
What factors impact prevalence?
Direct
1. Calculate the observed rate by strata
2. Standardize the population
3. Calculate expected number of the event of interest
4. Calculate sum of expected events
5. Use the sum divided by the total standardized pop to find the adjusted rate
Indirect
Standard mortality ratio: Total observed deaths in a pop / total expected deaths in a pop
Indirect adjusted rate = SMR x crude rate
Number of expected deaths found by applying the age-specific rates of the standard population to the population of interest