Epidemiology Midterm Exam 2024

definition of epidemiology? - The study of the distribution and determinants of health-related states or events in specified time and place. what are the three C's that epidemiologists do? - count compare communicate uses of epidemiololgy? - - helps look for causes of a disease - establish presence of an epidemic - helps identify syndromes and diseases - determines individual risk of disease epidemic definition? - new cases of a disease in a given population and period during a rate that IS GREATER THAN the expected amount of cases of that disease endemic definition? - disease with an ongoing expected level of occurence pandemic definition? - global epidemic (affects multiple countries) what is primary prevention? - preventing the initial development of a disease examples of primary prevention? - - condoms - vaccines - PPE - mosquito repellant what is secondary prevention? - goal is to stop the disease in early stages (before symptoms develop) examples of secondary prevention? - - routine screening tests for diabetes and blood pressure - pap smear what is tertiary prevention? - occurs in advanced/chronic conditions. goals are to limit disabilities from the disease examples of tertiary prevention? - - physical therapy - speech therapy - occupational therapy is obesity contagious? - no its not dont try it epidemiology vs infectious epi? - - infectious epi is two or more populations and regular epi is one population - infectious epi the cause is often known - regular epi the cause is unknown and you gotta find that out how many populations does infectious disease epidemiology work with? - two populations is there always a cause of a disease in infectious disease epidemiology? - not always what is a vector? - the living organism that transmits and infection like mosquitoes or ticks What is a resevoir? - where the agent (infectious agent) resides in its natural environment R0 is what - the reproduction number what is the epidemiologic triad? - - agent of infection - the host - the environment examples of an agent of infection? - - virus - bacteria how to calculate infectivity? - number infected / number susceptible how to calculate pathogenicity? - number with clinical sign of disease / number infected how to calculate virulence? - number of deaths / number of disease what is the reproduction number? - average number of secondary cases a single infectious case will cause in a susceptible population calculation for reproduction number? - p x c x d p = probability of transmission per contact c = contacts per unit time d = duration of infectiousness what disease has a very high reproductive number? - measles (thus you need a high vaccination rate) what is the effective reproduction number? - R0 but when part of the population is not fully susceptible how to calculate effective reproduction number? - R = R0 - (p x R0) p = proportion of people that are immune what is the herd immunity threshold? - minimum amount of population that needs to be immunized to obtain herd immunity how to calculate herd immunity threshold? - p 1 - 1/R0 p = proportion to gain herd immunity what is sporadic level of occurence? - occasional cases at irregular intervals what is disease control? - suppressing outbreaks but the agent continues circulation what is disease eradication? - complete elimination of the the disease AND the agent from a population problem with disease eradication? - loss of herd immunity develops (ex. smallpox) five domains of social determinants of health? - economic stability education access and quality health care access and quality neighborhood and the build environment social and community context is morbidity harder to measure than mortality? - yes what is YPLL - years of potential life lost predetermined end point age minus age of the decendent who died prior to that age what is YPLL useful for? - ranking the leading causes of death (mortality) what is DALYs - disability-adjusted life years DALY = YPPL + YLD (years lost to disability) what is QALYs - quality adjusted life years epidemiological sequence three overall steps - 1. descriptive epidemiology 2. analytical epidemiology 3. take public health action steps of descriptive epidemiological sequence? - 1. observe phenomenon of interest and verify diagnosis 2. count the cases/events 3. relate cases with the population at risk 4. make comparisons with past similar events steps of analytical epidemiology? - 5. develop a hypothesis 6. test a hypothesis 7. make conclusions based on evidence 8. conduct an experiment to validate hypothesis steps of taking public health action? - 9. disseminate the results 10. plan and implement intervention 11. evaluate the results of the intervention and modify the model as needed types of primary study designs? - - descriptive studies - analytical studies what is a descriptive study? - describing an outcome