All Flashcards
What value is measured in case control studies?
Odds ratio
What value is measured in cohort studies?
Relative risk
1 standard deviation corresponds with what percentage of the population?
68%
2 standard deviations correspond with what percentage of the population?
95%
3 standard deviations correspond with what percentage of the population?
99.7%
Which value is most important for a screening test?
High sensitivity; lowest test value that detects subjects with the disease
Which value is most important for a confirmatory test?
High specificity; highest test value that correctly identifies all subjects without the disease
NNT
1/absolute risk reduction
NNH
1/attributable risk
Absolute risk reduction
c/c+d - a/a+b
Attributable risk
a/(a+b) - c/(c+d)
Drug clearance
Vd x Ke (elimination constant)
Loading dose
LD = (Cp*Vd) / F (f = 1 for drugs given IV)
Maintenance dose
D = (CpCLT) / F
Renal celarance
C = (U*V)/P (U = urine concentration, P = plasma concentration, V = urine flow rate in mL/min)
GFR
U*V/P (e.g. for inulin)
RBF
RPF/(1-Hct)
Filtration fraction
GFR/RPF
Which values depend on disease prevalence/incidence?
PPV, NPV
Which values are fixed and don’t depend on disease prevalence/incidence?
Sensitivity and specificity
Coefficient of variation is an inverse measurement of what?
Precision (reproducibility)
