# Step I Equations

## Terms

undefined, object
copy deck
Prevalence
Prevalence = Incidence x Duration
Sensitivity
dz+/test+ divided by total dz+
True positive ratio
a/(a+c)
Specificity
dz-/test- divided by total dz-
True Negative ration
d/(b+d)
Positive Predictive Value
dz+/test+ divided by total test+
a/(a+b)
Negative Predictive Value
dz-/test- divided by total test-
d/(c+d)
Odds ratio
odds of having disease in exposed group divided by odds in unexposed group
quantitate how odds change with exposure
(a:b)/(c:d)
Relative Risk
dz risk in exposed group divided by dz risk in unexposed group
a/(a+b)/c/(c+d)
Attributable risk
a/(a+b) - c/(c+d)
Confidence interval
mean +/- 1.96(SEM)
SEM = (std dev)/sqrt(n)
Metabolism of FA
Acyl CoA prod = -2 ATP
Acyl CoA to Acyl CoA and Acetyl CoA = 5 ATP
Acetyl CoA in TCA cycle = 12 ATP
Cardiac Output
O2 consumption/(PaO2-PvO2)
Mean Arterial Pressure
MAP = CO x TPR
MAP = 0.3 Systolic P + 0.6 Diastolic P
Stroke Volume
CO/HR or ESV-EDV
Ejection Fraction
SV/EDV
Glomerular Filtration Rate
GFR = CL|inulin
GFR = (Ui x V)/Pi
Effective Renal Plasma Flow
ERPF = CL|pah
ERPF = (Upah x V)/Ppah
ERPF is essentially RPF
RBF = RPF/(1-Hct)
Volume of distribution
Vd = amt drug in body/plasma concentration
[mL]
assume concentration is same in all body compartments
Vd for plasma bound drugs
Vd = 0.03 L/kg << plasma volume
Vd for lipid soluble drugs
Vd . 10 L/kg > plasma volume
Clearance
CL = rate of elim/plasma concentration
CL = ke/plasma concentration
[mL]
hypothetical volume completely cleared of drug per unit time
Half-life
t1/2 = 0.7(Vd)/CL
6-7 half-lives to get to 100%