Epi test

  1. sensitivity
    • proportion of peopke w/the disease who have a positive test for the disease
    • Sensitivity = a/(a+c)
    • (TP / (TP + FN)
  2. Specificity
    • proportion of people withou the disease who have a negative test
    • Specificity = d/(b+d)
    • (TN / (TN + FP))
  3. Positive predicitve value
    • Positive Predictive Value = a/(a+b)
    • (TP / (TP + FP))
  4. Negative Predictive Value
    • NPV = d/(c+d)
    • (TN/ (TN + FN)
  5. Bias
    • any trend in the collection, analysis, interpretation, publication or review of data that canlead to conclusions that are systematically different from the truth
    • Selection bias – comparisons between groups that differ in ways other than the mainfactors being studied
    • Measurement – measurement different between the 2 groups
    • Confounding bias – if factor associated with actual cause-
    • Bias can often be prevented by proper study design and corrected through analysisbut the role of chance can only be reduced not eliminated by these measures
  6. Internal Validity
    the degree to which the results of a study are correct for the sample of patients being studied
  7. external validity
    the degree to which results of an observation hold true in other settings
  8. cluster
    occurence of a group of cases in a circumscribed place and time (anecdotal evidence)
  9. epidemic
    occurence of a disease at a rate greater than expected
  10. pandemic
    worlwide epidemic; epidemic crossing continental borders
  11. endemic
    habitual presence of a disease within a given geographical area
  12. disease transmission
    mechanism by which an infectious agrent is spread from a source or reeservoir to another person
  13. point source outbreak
    common source outbreak where the exposre ocurs in less than one incubation period
  14. continuous source outbreak
    common source outbreak where the exposure occurs over multiple incubation periods
  15. propogated epidemic
    transmission occurs from person to person
  16. primary prevention
  17. secondary prevention
  18. tertiary prevention
  19. approaches to prevention
  20. predictive value
  21. reliability
  22. epidemiology
    the study of the distribution and determinants of healh related states or events in specified human populatios and its application to the control of health problems
  23. biostatistics
    help us understad the role of chance
  24. descriptive epidemiology
    understand and describe the epidemiological triad and concepts of person, place, and time; no interventions provided; assessment of potential causes
  25. ecological studies
    • aka population or correlation studies
    • compare disease rates b/w populations
    • exposure is only known for groups, not individuals in the groups
  26. incidence
    number of NEW cases of disease that occur during specified period of time in a population at risk
  27. cumulative incidence (CI)
    incidence when all individuals are at risk for the entire period of time studied
  28. incidence Rate/density (ID)
    dfft individuals observed for different lengths of time; denominator is the sum of the lengths of time (often expressed as person-years)
  29. crude mortality rate
    the mortality rate in a population for all causes of death during a given time period
  30. cause specific mortality rate
    the number of deaths from a specified cause per 100,000 person-years at risk
  31. case-fatality rate (CFR)
    death rate from a specific disease among individuals during a specified period of time (ie. proportion of patients who die of a disease)
  32. Attack Ratio (AR)
    incidence of disease among a population at risk observed for a limited period of time, often due to a very specific exposure
  33. Birth rate
    number of live births in a population over a given period, usually a year
  34. General fertility rate
    live births in a population with the denominator restricted to the number of women of childbearing age over a given period
  35. steady state assumptions
Card Set
Epi test