Equation Review Flashcards
(54 cards)
Sensitivity
Sensitivity = TP / (TP + FN)
Specificity
Specificity = TN / (TN + FP)
Positive predictive value
PPV = TP / (TP + FP)
Negative predictive value
NPV = TN / (TN + FN)
Relative risk
[a/(a+b)]/[c/(c+d)]
Attributable risk
[a/(a+b)]-[c/(c+d)]
Number needed to treat
1/absolute risk reduction (ARR)
1/[Event Rate (control) - Event Rate (treatment)]
Number needed to harm
1/attributable risk increase (ARI)
1/[Event Rate (treatment) - Event Rate (placebo)]
Hardy-Weinberg equilibrium
p^2 + 2pq + q^2 = 1
p + q = 1
Henderson-Hasselbalch equation
pH = pKa + log ([HCO3-]/ 0.03 PCO2)
Volume of distribution
Vd= (amount of drug in the body) / (plasma drug concentration)
Clearance
CL = (rate of elimination of drug) / (plasma drug concentration)
Half-life
t1/2 = 0.7 x Vd/CL
Loading dose
LD = Cp x Vd/F
Maintenance dose
MD = Cp x CL/F
Cardiac output
CO = stroke volume * heart rate CO = Rate of O2 consumption/(arterial O2 content - venous O2 content)
Mean arterial pressure
MAP = cardiac output * total peripheral resistance MAP = 1/3 systolic + 2/3 diastolic
Stroke volume
SV = end diastolic volume - end systolic volume
Ejection fraction
EF = (stroke volume / end diastolic volume) x 100
Resistance
R = driving pressure/flow R = 8η (viscosity) x length / (∏r^4)
Net filtration pressure
Pnet = (Pc - Pi) - (?c -?i)
Glomerular filtration rate
GFR = U inulin x (V/ P inulin) = C inulin
Glomerular filtration rate (In terms of hydrostatic & oncontic pressures)
GFR = Kf [(P GC - P BS) - (? GC - ? BS)]
Effective renal plasma flow
ERPF = U PAH x (V/ P PAH) = C PAH
