Rapid Review: Equations Flashcards
Sensitivity
Sensitivity = TP / (TP+FN)
Specificity
Specificity = TN / (TN+FP)
Positive Predictive Value
PPV = TP / (TP+FP)
Negative Predictive Value
NPV = TN / (TN+FN)
Odds Ratio (For Case-Control Studies)
Odds Ratio = (a/c)/(b/d) = ad/bc
Relative Risk
Relative Risk = a / (a+b) ÷ c / (c+d)
Attributable Risk
Attributable Risk = a / a+b - c / c+d
Number Needed To Treat
1 / Absolute Risk Reduction
Number Needed To Harm
1 / Attributable Risk
Body Mass Index
BMI = (Weight In Kg) / (Height In Meters)2
Hardy-Weinberg Equilibrium
p2 + 2pq + q2 = 1
p + q = 1
Volume Of Distribution
Vd = Amount Of Drug In The Body / Plasma Drug Concentration
Half-Life
t½ = 0.7 x Vd / CL
Drug Clearance
CL = Rate Of Elimination Of Drug / Plasma Drug Concentration
CL = Vd X Ke (Elimination Constant)
Loading Dose
LD = Cp x (Vd / F)
Maintenance Dose
MD = Cp x (CL / F)
Cardiac Output
CO = Rate Of O2 Consumption / Arterial
O2 Content - Venous O2 Content
CO = Stroke Volume x Heart Rate
Mean Arterial Pressure
MAP = Cardiac Output x Total Peripheral Resistance
MAP = 2/3 Diastolic + 1/3 Systolic
Stroke Volume
SV = CO / HR = EDV - ESV
Ejection Fraction
EF = SV / EDV = EDV - ESV / EDV
Resistance
Resistance = Driving Pressure (ΔP) / Flow (Q)
= 8η (Viscosity) x Length / πr4
Net Filtration Pressure
Pnet = [(Pc - Pi) - (πc - πi)]
Jv = Net Fluid Flow = (Kf) (Pnet)
Renal Clearance
Cx = UxV / Px
Glomerular Filtration Rate
GFR = Uinulin x V/Pinulin = Cinulin
GFR = Kf [(PGC - PBS) - (πGC - πBS)]
