cbse equations Flashcards
filtration fraction
FF = GFR / RBF
GFR is about 120
RPF is about 600 (renal plasma flow)
in healthy FF is about 20% of RPF
clearance
Cs + [urine concentration of S] x [urine flow rate] / [plasma concentration of S]
GFR can be obtained by ?
RPF?
clearance of creatine
clearance of PAH
absolute risk increase?
number needed to harm?
adverse event rate in control and experimental then subtract adverse in experimental from control
NNH = 1/ the absolute risk increase
sensitivity
people with the disease that test positive
want this number high to know picking up on diagnosis
higher = better at ruling out disease
SCREENING diseases
A / A+C
true positive / true positive + flase negative
rule OUT disease
specificity
true negative
without the disease who test negative
closer to 100 p = better at ruling in
low false positive
confirm after positive screen
SPIN
D/D+B
true negative/ true negative + false positive
type 1 error
shows a relationship tht does not really exist
type II error
study fails to show a relationship that does exist
beta error
Vd=
amount of drug given (IV)/ [drug] plasma
low Vd = intravascular space and large/ charged molecules + bound
medium = intrvascualr and extracellular
large = able to get to all tissues and including fat
- usually small and lipophilic molecules
clearance of a drug
0.7 X Vd/ t 1/2
1/2 life =
.7 X Vd / clearance
hardy weinberg equations
p+q=1
P^2 +2pq+q^2=1
p^2= frequency of homozygous for p
q^2 = freq for homozygous for q
2pq= frequency of heterygosity
positive skew graph in terms of mean median and mode
negative?
shifted to the left
tail to the right
mean > median
median > mode
mode > median
median >mean
case control study
w/ disease and w/out groups
then look back at it
look at some exposure risk
retrospetive and observational
purely observational
- no intervention
*used to identify risk factors for diseases
NOT causal -
yields an odds ratio!!
odds ratio
study design and equation?
AxD divided by BxC
cohort study
group of people that has something in common
compare them to group that have not had that exposure and then follow them
*purely observational
either retrospective or prospective
formula associated with cohort study
relative risk
or risk ratio
relative risk equation
A/A+B divided by C/C+D
cross sectional study
looks at a population at a point in time
(ex dx of COPD at a time)
or ask about a risk factor
- exposed to 2nd hand smoke on that day
known as PREVALENCE
observational study
what does cross sectional show
prevalence