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Epidemio, Ethics USM
Question | Answer |
---|---|
differentiate bw prevalence and incidence | prevalence is the no of cases at a given time, incidence is the no of new cases over a period of time |
define PPV in words, in eqn | probability of those w + test really have dz; those + tests with dz divided by everybody who had a + test |
how does prevalence affect PPV | higher prevalence, higher PPV |
how does specificity affect PPV | higher specificity, higher PPV |
define NPV in words, in eqn | probability that those w - test really don't have dz; those - tests without dz divided by everybody w - test |
how does sensitivity affect NPV | the more sensitive the test, the higher the NPV |
how does prevalence affect NPV | the lower the dz prevalence, the lower the NPV |
what's + likelihood ratio tell you (in words) | for a + test, the ratio of those that have the dz v. those that don't [true + / false +] |
what's + likelihood ratio in an eqn | eqn= + test + dz / + test - dz |
define + likelihood ratio in terms of sensitivity and specificity | sensitivity / (1-specificity) |
define specificty in words, in eqn | probability pt + dz will have + test; % of ppl w dz whose test is + [= + dz + test / all + dz ] |
define sensitivey in words, in eqn | probability pt - dz will have - test; % ppl - dz w - test [= - dz - test / all - dz] |
explain how raising the glu cut-off for DM will affect false negatives and false positives | fewer false positives, more false negatives |
explain how raising the glu cut-off for DM dx affects sensitivity and specificity, PPV and NPV | lower sensitivity, higher specificity, higher PPV, lower NPV |
what's - likelihood ratio tell you (in words) | for a - test, the ratio of those that have the dz v. those that don't [true - / false -] |
what's - likelihood ratio in an eqn | eqn= - test + dz / - test - dz |
define - likelihood ratio in terms of sensitivity and specificity | eqn=(1-sensitivity) / specificity |
what is the pretest probability | dz prevalence |
what's absolute risk | incidence of dz |
what's attributable risk? Aka? Eqn | risk difference, how much the risk of the dz is due to exposure; =incidence in ppl exposed - incidence in ppl not exposed |
what is relative risk? Aka? Eqn | risk ratio, how much more likely an exposed grp is to get the dz than unexposed; = incidence in exposed / incidence in unexposed |
what type of studies report odds ratios, what does it mean | cohort study; relative risk of person w dz to have had exposure vs. person w/o dz to have had exposure |
eqn for odds ratio | AD/BC |
define odds in terms of probability | odds=probability/(1-probability) [ie probability it will happen/probability it won't happen] |
eqn for probability in terms of odds | probability= odds/(1+odds) |
define alpha error, beta error | alpha=type I; saying there's a diff when there really isn't one; beta=type II, saying there's no diff when there really is one |
what are essential elements of informed consent | BRAIN=Benefits, risks, alternatives, indications, nature of intervention |
difference bw competence and decision making capacity | competence is pt's legal capacity to make decisions, as assessed by court; decision making capacity is the medical term |
DNI and DNR are exs of | living will |
difference bw wdrawal of care and withholding care | none legally |
define therapeutic privilege | MD can withhold info from pt if the info would severely harm them or undermine their decision making capacity |
what are 4 key components of malpractice lawsuit | duty, dereliction of duty, damage, and the damage was directly caused by dereliction of duty |
what's the burden of proof for malpractice | preponderance of evidence (not beyond a reasonable doubt) |