Epidemiology Flashcards
(29 cards)
Epidemiology
The study of the occurrence and distribution of health related events, states, and processes in specified populations, including the study of the determinants influencing such processes, and the application of this knowledge to control relevant health problems
Epidemiology asks
Why does a disease develop in som people and not others
How is it transmitted
What is the natural history
What is the burden to the community
How can we use this information to reduce the disease
Importance of epidemiology
- allows for identification, classification, and planning for disease control
- allows for understanding of causing factors of disease
- allows for public health initiatives
- allows for allocation of resources
What do we need to know to answer the question “my mother has AMD, will I get it?”
What is the prevalence of AMD in:
- patient over 50?
- Caucasian?
- females?
- children of AMD pateitns?
- smokers?
Prevalence
How many people have it
Prevalence of AMD over 50
2.5% of caucasians
prevalence of AMD in all ages
2% in whites (2x)
.9% black
.9% in Hispanic
prevalence of AMD in females/males
65%/35%
Much greater in females
Prevalence of AMD in chidlren of AMD patients
Odds ratio 6.6
6.6x more likely
Prevalence of AMD in smokers
Relative risk if 3.29
3.29x more likely
When someone with drusen and RPE atrophy in the retina asks “I’ve read about taking vitamins, will these hope me?” How do we answer this question?
We have to know
What does the evidence say? “Evidence based practice”
How good is the research?
AREDS I and II (RCT)
Conclusion of AREDS I
Those with extensive intermediate size druse, at least 1 large druse, noncentral GA in 1 or both eyes, or advanced AMD or vision loss due to AMD in 1 eye, and without contraindications such as smoking, should consider taking a supplement of antioxidants plus zinc such as that used in this study
Clinical epidemiology
The application of epidemiological knowledge, reasoning, and methods to study clinical issues and improve clinical care
The study of anything that happens to people “that which befalls man”
Epidemiology
Germ theory
Girolamo fracastorius
- microorganisms cause diseases
- epidemics, ways infection can be transmitted
1400-1500
Demography
The statistical study of populations based on size, density , age and vital stats
- first mortality tables
- important in study disease trends
John Graunt (1600)
First clinical trial
James Lind (1700)
- sailors with scurvy
- adding citrus fruits to sailors diets improved condition
- later understood to be caused by vitamin C deficiency
First modern census
William Farr (1800)
- a count or survey of a population
- lead to the first classification of diseases lead to international classification of diseases (ICD codes)
John snow
1800
- cholera-intestinal bacterial infection
- 19th century theory: caused by a cloud on earths surface
- snow believed it was due to contaminated water
- went from house to house, recorded deaths and which company supplied water
- when company moved pump, fewer deaths
Point of John snow figuring out cholera
- they didnt know anything about the biology of the disease- this was based entirely on observational data
- caused by contaminated water
Haiti
- 1 million (10% of population) cases of cholera
- introduced by poor sanitation by UN peacekeepers following earthquake
- endemic in Haiti
- large decrease in 2017
- incidence now 1%, goal is .1%
Epidemic of drugs in Fl
More deaths from heroin in Fl right now
Not all epidemics are “infectious”. Can be drugs
Disease trends over time
- 20th century deaths
- early part of century-more communicable diseases-pneumonia, influenza, TB
- later on, chronic diseases-cardiovascular, diabetes, cancer
Large scale cohort studies
Framingham, Beaver Dam, Blue Mountains, Rotterdam
