MD EVIDENCE BASED DENTISTRY Flashcards
HEIRCHY OF EVIDENCE:
BEST AND WORS TYPE OF STUDY?
Best: META ANALYSIS (analysis combines multiple studies)
Worst: IN VITRO STUDIES (test tube)
epedemiological studies
quantify disease status in a community
survey or measurement taken to represent a snapshot in time, prevelance
case control study
cross sectional study
prospective cohort study
retrospective cohort study
CROSS SECTIONAL
same day sudy
people with a condition are compared to people without it (control) in the past, odds ratio
case control study
cross sectional study
prospective cohort study
retrospective cohort study
CASE CONTROL STUDY
cohort followed thorugh time to see who develops a diseae, incidence and related risk
case control study
cross sectional study
prospective cohort study
retrospective cohort study
PROSPECTIVE COHORT STUDY
look back after following cohort and decide what disease you want to look for, incidence and relative risk
case control study
cross sectional study
prospective cohort study
retrospective cohort study
RETROSPECTIVE COHORT STUDY
A scientist wanted to do a study on how many alcholohic patients have oral cancer so he took a sample size of an area.
case control study
cross sectional study
prospective cohort study
retrospective cohort study
CROSS-SECTIONAL STUDY ( survey to find prevelance)
a researcher is trying to find link between tobacco smoking and lung cancer
case control study
cross sectional study
prospective cohort study
retrospective cohort study
purpose of analytical and observational studies?
detemrine the etiology (cause) of disease
what is the purpose of CLINICAL TRIAL?
isolate one factor and examine its contribution to patients health by holding all other factors as constant as possible
best tool for doing an experimental study?
RANDOMIZATION
best type of clinical trial to do
single blind
double blind
random sampling
random allocation
DOUBLE BLIND !!
for frequency distributions, what is the shape of NORMAL DISTRIBTUION?
BELL SHAPED
IMAGE : bell shape is middle red
How do we measure the RANGE of a set of numbers?
maximum - minimum = range
how spread out individual values are from the mean is called what?
VARIANCE
square root of vairance is called what?
standard Deviation
how do we find SD?
squar root of variance
what does a large SD tell you about numbers?
the larger the SD the more spread out the number are
reliability and validity:
which one is precicision and which one is accurate?
Reliability: Precision
Validity: accuray
KNOW THIS CHART !!!
High TN related to FP: High specificity
High amount of TP relative to FN: high sensitivity
Success: HIGH TP and TN
FAILS: FP and FN
How is STATISTICAL SIGNFICANCE (P-VALUE) defined?
probability 2 variables UN-RELATED
what do you do about the null hypothesis if p< .05?
reject null hypothesis: statistically significant
null hypothesis: soemthing we belive to be true!
JOn says they have a good technique to roll a 6 on a dice more frequently.
Null hypothesis: researcher states no relationship between technique you use and rolling a 6 ( believed it to be true)
jon poes null is rejected because means likely that he is right
p
average male baby in texas is 7 lbs. a nurse suspects that baby weight has went up in recent years and collect data to see.
null hypothsis (scientist) H0: 7 lbs
alternative hypothesis (midwife) H1 : >7 lbs
NULL HYPOTHESIS IS WHAT WE EXPECT TO SEE BASED ON KNOWLEDGE WE HAVE
midwife wants null rejected.
what does the researcher try to do to the null hypothesis ?
disprove, rejectm or nullify
THERE IS NO DIFFERENCE B/W CARIES PREVELANCE IN FLUORIDATED VS NON FLUORIDATED WATER
What is the null?
when is the null hypothesis rejected?
when is null accepted?
what is a type 1 and type 2 error
EXTREMELY IMPORTANT !!!
Null: no difference b/w fluoridated vs nonfluoridated
Reject null: there is a difference
when its rejected: True positive
TYPE 2 ERROR : accepted null that shouldve been rejected
TYPE 1 ERROR : rejected null whenever it was true
We accepted null hypothesis: when there is true negative
what is a type 1 error
;
when we REJECT null whenever it is TRUE
what is type 2 error?
ACCEPT null whenever it should be REJECTED
what is correlation coefficent (r) ?
measure represents strength of relationship b/w 2 quantitative variables
always between : -1 and 1
-1 (lie on perfect negative line)
+1 (lie on perfect positive line)
r=0 means no linear relationship
measures association b/w 2 categorical values ?
T-Test
Z-test
ANOVA
CHi-squared test (X2)
chi-squared
ex: prefer cats or dogs both men and women
measures statistical differences b/w 2 means, small sample size
T-Test
Z-test
ANOVA
CHi-squared test (X2)
T-test
if T-value lower than number then dont rekect null if higher then reject.
measures statistical differences b/w 2 means, large sample size
T-Test
Z-test
ANOVA
CHi-squared test (X2)
Z-test
used to test differences between 2 or more means
T-Test
Z-test
ANOVA
CHi-squared test (X2)
ANOVA( analysis of variance)
match:
qualitative, quantitative
Descriptive, numbers
qualitative: DESCRIPTIVE
quantitative: numbers
what test is for qualitative vs quantitiatve?
X2
T-test
Z-test
NOVA
qualitative: X2
quantitative: t test/ z test/ nova
hair type, blood type, etc is a type of what?
qualitative or quantitative
qualitative (NOMINAL): names and labels
which is qualitative and which is quantitative? give examples
ordinal
interval
nominal
ratio
Qualittive:
nominal (names or labels): hair type, blood type etc
ordinal (ranking): socioecnomic status, educational level etc.
Quantitative:
ordinal: ranling
interval (value range; measure on scale): temp, sat scores
ratio: range of values with clear definition of 0: rxn rate, pulsem weight
X and Y:
whch one is independent and dependent
X: indepepndent
Y: dependent
WHAT ARE COMPONENTS OF SCIENTIFIC PAPER IN ORDER ???
BOARD ****
TITLE
ABSTRACT (summary; spark notes)
INTRODUCTION
METHODS (info about pop being tested)
RESULTS
DISCUSSION
CONCLUSION
REFERENCES
TAIMR-DCR
