Epidemiology and social Causation of Disease Flashcards
Revision
What is Epidemiology?
Study of the frequency, distribution and determinants of disease in populations
What is a cause?
An event, condition or characteristic that preceded the disease/outcome without which the disease/outcome would not have occurred at all (or would have occurred at a later time).
What is a risk factor?
An attribute or exposure (e.g. aspect of personal behaviour or lifestyle, environmental exposure or inborn or inherited characteristic) that is associated with an increased probability of a specified outcome (i.e. incidence of disease).
Not necessarily causal).
How can you use risk factors to improve prevention?
EPIDEMIOLOGY
Understanding the relationship between exposure to risk factor and risk of disease.
Knowledge of distribution of exposure to risk factors in the population.
PUBLIC HEALTH
Evidence of efficacy of intervention to remove/reduce risk factor.
Understanding political, economic, psychological and social issues involved in implementing intervention.
What are some sources of health information?
Mortality (deaths) - Death certificates - Annual statistical returns Morbidity (disease) - Disease registrations - GP surveys - Hospital admissions data Quality of life
How do you calculate mortality rates?
(No Deaths/Population at risk) X 1000
What are the 3 different mortality rates and what do they mean?
Crude death rate:
Mortality rate for whole population
Age-specific mortality rats:
Mortality rates for specific age/sex groups
Cause-specific mortality rates:
Mortality rates for specific causes of death.
What is the overall mortality rates and what does it mean?
Overall mortality rate (crude death rate) depends on the age/ sex structure of the population.
A country with a higher proportion of old people will have a higher number of deaths and a higher CDR.
What does Standardisation allow us to do?
Standardised mortality rates permit comparison of mortality between populations with different age profiles.
Rates are compared with hose in a standard population (EU, UK, US etc).
Age standardisation and sex standardisation are the most common.
The standardised mortality ratio (SMR) compares the expected rate with the observed rate.
What do population pyramids show?
Population pyramids show distribution of population across age groups and sex.
Population pyramids show distribution of population across age groups and sex.
They can show changes due to various events.
They can also be used to show the effects of changes in birth and death rates.
What are incidence and prevalence used to describe?
Mortality rate is a poor measure of disease frequency in a population.
Incidence and prevalence rates used to describe morbidity/disease frequency in a population
How is incidence rate calculated?
(Number of NEW cases of a disease occurring in a population during a specific period of time)/(Number of persons exposed to risk of developing the disease during that period of time)
Usually expressed per 1000
How is prevalence rate calculated?
(Number of cases of a disease in population at a specific point in time)/(Number of persons at risk of having the disease at that point in time)
Usually expressed per 1000
What is Quality of life and what are some aspect that are included in quality of life?
Objective measures can miss the human dimension. What do people feel about their illness? How does it affect their lives? What are their expectations? Is the cure worse than the illness? Palliative care End of life decision?
What is all this data used for?
Assessing need for health care Planning medical/nursing services Health Policy Prediction of outbreaks Audit of performance
