epidemiology final exam spring 2017

  1. What prevention reduces the occurrence of disease. takes place during prepathogenesis
    Primary prevention
  2. what prevention reduces the progress of disease. Takes place during the pathogenesis phase of natural history of disease
    secondary prevention
  3. What prevention limits disability from disease. the disease has occurred and has been treated but some form of rehab limits progression or minimizes side effects
    Tertiary prevention
  4. What does screening do
    • sorts out those who are at risk and those who are not
    • do not diagnose but identify risk
    • is preliminary and results must be confirmed by a diagnosis
    • secondary prevention is screening happens
  5. What is the purpose of screening and what instruments can be used
    • to separate those who "might" from those who "don't" have disease
    • instruments: lab test, thermometer, scales, questionnaires
  6. What is Content validity
    • used to measure the validity of survey instruments
    • the items in a questionnaire seem to be valid for measuring what they are supposed to measure
    • Also referred to as rational or logical validity
  7. What are the two types of validity under Criterion-referenced
    • predictive validity
    • concurrent
  8. what does criterion-referenced mean
    found by correlating a measure with an external criterion of what's being assessed
  9. What is predictive validity under criterion-referenced
    • ability to predict some attribute
    • positive correlation with future incidence
    • also know as statistical validity
  10. What is concurrent validity under criterion-referenced
    • correlating a measure with an alternative measure of the same phenomenon taken at the same point in time
    • ie: inversion and hospitalization for breathing problems OR inversion and depression
  11. It is possible for a measure to be highly _______ but not _______ BUT it is not possible for a measure to be ________ and not __________
    • reliable
    • valid
    • valid
    • reliable
  12. What are three sources of unreliability and invalidity
    • Measurement bias
    • halo effect
    • social desirability
  13. What is measurement bias in connection with sources of unreliability and invalidity
    constant errors that are introduced by a faulty measuring instrument
  14. What is halo effect in connection with sources of unreliability and invalidity
    a general opinion has been formed prior to conducting an evaluation (like yearly evaluations by supervisors)
  15. What is social desirability in connection with sources of unreliability and invalidity
    answer questions in manner that corresponds to what may be the socially desired behavior
  16. What is sensitivity as a measure of validity
    • ability of the test to identify correctly all screened individuals who actually have the disease
    • screened positive and have disease
    • has to do with the tool used
  17. What is specificity as a measure of validity
    • the ability of a test to identify only non diseased individuals who actually do NOT have the disease
    • non diseased and test negative
  18. If screening test are unable to perform sensitivity and specificity what happens?
    • cases are missed OR
    • those who do not have the disease will be referred for additional diagnostic testing (which could cost lots of money)
  19. What is predictive value (+)
    proportion (so talking about the actual number) of individuals screened positive by the test who actually have the disease (according to the gold standard)
  20. What is predictive value (-)
    measure for those screened negative by the test and do not have the disease
  21. What is the epidemiologic triangle
    • at the three corners are HOST, AGENT (disease/cause), ENVIRONMENT
    • this model helps explain the etiologic agent, reservoir, portal of exit, transmission, portal of entry, and susceptible host
  22. What are the 6 characteristics of ID Agents
    • infectivity
    • pathogenicity
    • virulence
    • toxigenicity
    • resistance
    • antigenicity
  23. What is infectivity as a characteristic of ID agent
    ability to enter and multiply in host and produce infection
  24. What is pathogenicity as a characteristic of ID agent
    ability to cause disease in host
  25. what is virulence as a characteristic of ID agent
    severity of disease
  26. what is toxigenicity as a characteristic of ID agent
    capacity to produce a toxin
  27. what is resistance as a characteristic of ID agent
    ability of disease agent to survive adverse environmental conditions (resistance versus fragile)
  28. What is antigenicity as a characteristic of ID agent
    ability to induce antibody production in host
  29. What does "active" mean in connection with disease specific defense mechanisms
    administer to host to mimic natural infection with little or no risk
  30. What is natural active
    immunity from infection
  31. What is artificial active
    infection with vaccine
  32. What does "passive" mean in relation to disease specific defense mechanisms
    antibody for short duration
  33. What is natural passive
    like pregnancy
  34. What is artificial passive
    given to exposed individual to protect against developing disease (ie immunoglobulin)
  35. What is direct transmission as a mode of transmission in the environment and examples of how this happens
    • person to person contact
    • sexual contact
    • respiratory infections
    • blood borne
    • fecal oral
    • requires a way out (portal of exit), mode of transmission, and a way in (portal of entry)
  36. What are the characteristics of an Attack Rate (which is a measure of disease outbreaks)
    • also an incidence rate
    • the # of new cases among all exposed during a time period
    • ALWAYS used in foodborne outbreaks
  37. What is the effect or exposure to a chemical or substance upon an organism
    Dose-Response (exposure(dose))
  38. What is the lowest dose at which a particular response may occur
  39. What is the time period between initial exposure and a measurable response
  40. what is the combined effect of several exposures
  41. Dose Response
    At what level or concentration of the dose does the organism respond
  42. Threshold
    • The accepted exposure level below which no adverse effects are observed
    • Knowing the threshold of an exposure is a major assumption when determining the dose-response relationship fro an exposure
  43. Latency
    Similar to incubation time.
  44. Synergism
    The combination has a greater effect upon health than the sum of the two independent exposures
  45. Human body has 2 environments? what are the barriers?
    • inside and outside
    • Skin
    • Gastrointestinal tract (gets it out)
    • Lungs (cough)
  46. Types of variables
    • Independent
    • Moderating/Intervening
    • Dependent/Outcome
  47. What is an independent variable?
    • similar to exposure variable -- a causal factor
    • stress, social incongruity, person-environment fit, life events
    • The things that life throws at us
  48. What is a moderating/intervening variable
    • also known as an intermediate variable
    • variables in the causal pathway between the independent and outcome variables
    • What we are made up of, what we have going for us
    • personality factors (type A behavior)
    • Culture
    • social support
    • lifestyle and behavior
  49. Dependent/outcome variables
    • variables affected by an independent variable
    • result of the independent and moderating variables
  50. What is the independent variable of social incongruity
    • when out of place
    • looking at effects of changes in residence; intra-generational mobility; husband-wife discrepancy in status
  51. what is included in dependent or outcome variables and some topics covered
    • include physical health, mental health, and affective states
    • some topics:
    • life and job dissatisfaction
    • mental health and stressors
    • premorbid psychologic factors and cancer
  52. dependent/outcome variable: mental health and stressors
    • depressed persons reported more physical illness than non-depressed
    • psychologic disorders: posttraumatic stress disorder and major depression
    • affective states: depressive symptoms
  53. What are characteristics of a good screening test
    • Simple
    • Rapid
    • Inexpensive
    • Safe
    • Acceptable
  54. What is construct validity
    The degree to which the measurement agrees with the theoretical concept being investigated
  55. Define Validity
    also known as accuracy.  It is measuring what you intend to measure. It give a true measure
  56. Three types of validity
    • content
    • criterion referenced (predictive validity, concurrent)
    • Construct
  57. How do you improve sensitivity
    the cut point to classify diseased should be moved farther in the range of the non diseased
  58. How do you improve specificity
    the cut point should be moved farther in the range of typically associated with the disease
  59. When the _______ of a disease falls the ________ falls and the ____________ rises.  Why important
    • prevalence
    • predictive value (+)
    • predictive value (-)
    • Any individual who has a positive screening test would have low probability of having the disease and an invasive or expensive diagnostic procedure would probably not be warranted
  60. What is indirect transmission
    • spread through an intermediary source
    • Vehicle water, food
    • fomite (inanimate object, door knob)
    • Vector - living insect or animal
Card Set
epidemiology final exam spring 2017
Final Exam epidemiology spring 2017