Card Set Information

2013-07-10 13:18:06

Show Answers:

  1. Sensitivity
    prob that patient with a disease will have positie test result, won't miss people with a disease, rules out those without dz (few false neg)
  2. Specificity
    prob that patient without disease will have a negative test result, rules in those with disease (low false positive)
  3. False neg and false positive ratio
    False neg ratio=1-sens

    False pos ratio=1-spec
  4. PPV
    prob that patient with a positive test actually has disease, more specific=high ppv, higher disease prevalence, higher ppv
  5. npv
    • prob that patient with neg test result doesnt have disease, more sensitive, higher nov.
    • lower disease prev, higher npv
  6. Positive likelihood radio
    • sens/1-spec
    • Fraction of patients with a disease who have a positive test divided by those without a disease who have a positive test
    • Shows the probability of a disease if the test is +
  7. negative likelihood ratio
    • 1-sens/spec
    • shows prob of disease are dec if test neg
  8. Cohort study
    • group of people assembled none who has the outcome of interest(the disease) but all who could experience that outcome. ¬†Followed over time and incidence of outcome is compared over exposure groups
    • Can be prospective or retrospective
  9. Case control study
    • series of cases identified and a set of controls sampled from the underlying pop to estimate the frequency of exposure in the population at risk of outcome. ¬†Compares frequency of exposure to a possible risk factor in two groups. ¬†
    • Ex: alcohol intake among individuals with breast cancer compared to that of people without breast cancer
  10. Relative risk
    • incidence in exposed people/incidence in unexposed
    • (a/(a+B))/(c/c(c+d))
  11. Odds ratio
    • estimate of relative risk that is used in case control studies
    • odds that disease person is exposed/odds that non diseased person is exposed
    • ad/bc