Sensitivity formula ✔️Ans -"Sensitivity =true positive/(true
positive +false negative) Note: more sensitive is closer to 1"
Specificity formula ✔️Ans -Specificity = True negative/(true
negative + false positive)
Precision definition ✔️Ans -how consistent the test results are
Accuracy formula ✔️Ans -"accuracy=(true positive plus true
negative)/total - how true the test results are"
Receiver operator characteristic ✔️Ans -"the cutoff value for
maximizing accuracy; describes the inverse relationship between
sensitivity and specificity (i.e. increasing specificity decreases sensitivity)"
Positive predictive value formula ✔️Ans -PPV=True
positive/(true positive +false positive)
Negative predictive value formula ✔️Ans -NPV= true
negative/(true negative + false negative)
Prevalence definition ✔️Ans -total number of cases at a given
time
Incidence definition ✔️Ans -new cases in a specfiic time peiod
Likelihood ratio formula ✔️Ans -"positive test =true positive
%/ false positive% OR negative test =false negative %/true negative % "
When is a 95% CI statistically significant ✔️Ans -"for mean: if it
doesn't cross 0; For OR/RR, if it doesn't cross 1"
When is RR done ✔️Ans -prospective studies
, When is OR done ✔️Ans -retrospective studies (would
overestimate the risk in prospective studies unless incidence in population
is <10%)
RR formula ✔️Ans -RR=incidence rate in exposed patients/
incidence rate in non-exposed patients
if RR >1, what does that mean ✔️Ans -the incidence in the
exposed group is higher than non-exposed group
Odds Ratio Formula ✔️Ans -OR = (# of exposed with disease
present X # of unexposed with disease absent)/(# of exposed with disease
absent x # of unexposed with disease present)
what looks at predictability? ✔️Ans -regression analysis, not
correlation coefficient
coefficient of variation (r squared) definition ✔️Ans -this
provides us with the %of information we can attribute from one variable to
another
linear regression vs multilinear regression ✔️Ans -linear is 1:1
independent to dependent variables, whereas multilinear is multiple:1
independient to dependent variables
logistic regression analysis ✔️Ans -done to determine which
variables are important to predicting the outcome
Therapeutic Index Formula ✔️Ans -TI= median toxic (lethal)
dose/median effective dose
Drug interaction with protease inhibitors ✔️Ans -Inhibit
CYP3A4
NNRTI that inhibits not induces ✔️Ans -delavridine
what SNP is a problem with carbamazepine ✔️Ans -HLA-
B*1502