RD EXAM Pass Class notes Questions
and Answers
Observational studies - ANS-the researchers do not change anything they just gather
info. The results measure association or correlation on causation.
Prospective studies - ANS-"watch and wait", collect data then wait for outcomes, key
outcomes measured after exposure. Ex. subclinical manifestations of heart disease
before heart attack, all RTCs
Retrospective - ANS-outcome measured before exposure
Cross sectional - ANS-"snapshot" exposures and outcomes at the same time, ie
NHANES
prevalence study
Case controlled - ANS-outcome then work backward to measure exposure
PPL with dx compared to controls
Cohort - ANS-exposure measured before the outcome develops
prospective and retrospective
Experimental studies - ANS-research that manipulates the environment
if the study is randomized infer causation, if not cannot infer anything
Positive correlation - ANS-x and y increase or decrease together
Negative correlation - ANS-as one variable increases, the other decreases
Correlation - ANS-= r, r ranges from -1 to +1, 0 = no relationship
Paired comparison test - ANS-aka preference test
2 samples rated for qualities
Tringle test - ANS-2 of the same sample 1 different, a judge has to pick the different
sample
Quantitative descriptive test - ANS-8-12 people, panelists trained on sensory
characteristics, rate the samples on these characteristics
Evidence Grades - ANS-I= Strong- IV weak/expert opinion
,V= insufficient evidence
Quantitive data - ANS-info can be measured and written in numbers, ex of research:
RCT looking at outcomes of group meetings on DM labs
Qualitative data - ANS-info about behavior, ie understanding the variety of childhood
experiences around food
validity - ANS-the extent to which a test measures or predicts what it is supposed to
internal difference between 2 groups real?
external = Can you generate to a large population
Reliability - ANS-the degree to which an assessment tool produces stable and
consistent results ie arrows around 1 point
are the results reproducible?
bias - ANS-related to accuracy and validity
how close is your measurement to 150 lbs?
= systematic error
random error - ANS-related to precision and reliability
how close are your measurements?
Sensitivity - ANS-the ability to ID a positive DX
a test with 100% would produce a positive result in everyone with the DX (no false
negatives)
Specificity - ANS-ability of a test to ID those without the DX
Prevalence - ANS-is the number of existing Dx cases during a period of time
= incidence x duration
overall = TP + FN/N
incidence - ANS-number of NEW cases that develop over a period of time
Odds ratio - ANS-a measure of association between a dependent and independent
variable mean, median, and mode
negative skew - ANS-mean is LOWER than median
Positive skew - ANS-mean is HIGHER than median
descriptive research - ANS-do NOT determine a relationship
qualitative research
case report/ study (novel dx)
Correlation/ecological studies
, Analytic research - ANS-experimental- cause can be found (RTCs)
observational- no cause-only association (quasi-experimental, cohort study, case-
control study, cross-sectional study)
nominal variables - ANS-no order ie gender, race etc
Ordinal scale - ANS-a scale of measurement in which the measurement categories form
a rank order along a continuum ie stage 1 cancer
numerical discrete - ANS-data with numbers (number of clinic visits), no set number
numerical continuous - ANS-on a continuum
ex. height, weight, time
Standard deviation - ANS-indicates the dispersion of data about the mean (average)
68% of observations lie within the range 1 SD of mean
32% of observations lie outside the range (rang = mean +/- 1 SD)
95% lie within +/- 2 SD of mean
P values - ANS-P< or equal to 0.05 is significant
the lower the P value the higher the statistical significance of the results
nasogastric tube - ANS-tube inserted through the nose into the stomach
less than 4 weeks
x-ray to make sure in place
Nasoduodenal/Nasojejunal - ANS-nose to the small intestines
less than 4 weeks
x-ray to make sure in place
Gastrostomy/Jejunostomy - ANS-surgically placed directly into the stomach or jejunum
used longer than NG tubes
used if pt cannot have a tube through mouth or throat or they vomit a lot
surgically placed
Percutaneous endoscopic gastrostomy/jejunostomy (PEG/PEJ) - ANS-fed through
mouth to stomach or jejunum can last months to years
complications: gastric content leakage and skin irritation, aspiration (PEG), bleeding or
bowel perforation (PEJ)
Endo placed
G tubes - ANS-prone to leakage, skin irritation, nausea, vomiting, and bloating
J tubes - ANS-increase dirrhea
no bolus feeds- risk of aspiration
and Answers
Observational studies - ANS-the researchers do not change anything they just gather
info. The results measure association or correlation on causation.
Prospective studies - ANS-"watch and wait", collect data then wait for outcomes, key
outcomes measured after exposure. Ex. subclinical manifestations of heart disease
before heart attack, all RTCs
Retrospective - ANS-outcome measured before exposure
Cross sectional - ANS-"snapshot" exposures and outcomes at the same time, ie
NHANES
prevalence study
Case controlled - ANS-outcome then work backward to measure exposure
PPL with dx compared to controls
Cohort - ANS-exposure measured before the outcome develops
prospective and retrospective
Experimental studies - ANS-research that manipulates the environment
if the study is randomized infer causation, if not cannot infer anything
Positive correlation - ANS-x and y increase or decrease together
Negative correlation - ANS-as one variable increases, the other decreases
Correlation - ANS-= r, r ranges from -1 to +1, 0 = no relationship
Paired comparison test - ANS-aka preference test
2 samples rated for qualities
Tringle test - ANS-2 of the same sample 1 different, a judge has to pick the different
sample
Quantitative descriptive test - ANS-8-12 people, panelists trained on sensory
characteristics, rate the samples on these characteristics
Evidence Grades - ANS-I= Strong- IV weak/expert opinion
,V= insufficient evidence
Quantitive data - ANS-info can be measured and written in numbers, ex of research:
RCT looking at outcomes of group meetings on DM labs
Qualitative data - ANS-info about behavior, ie understanding the variety of childhood
experiences around food
validity - ANS-the extent to which a test measures or predicts what it is supposed to
internal difference between 2 groups real?
external = Can you generate to a large population
Reliability - ANS-the degree to which an assessment tool produces stable and
consistent results ie arrows around 1 point
are the results reproducible?
bias - ANS-related to accuracy and validity
how close is your measurement to 150 lbs?
= systematic error
random error - ANS-related to precision and reliability
how close are your measurements?
Sensitivity - ANS-the ability to ID a positive DX
a test with 100% would produce a positive result in everyone with the DX (no false
negatives)
Specificity - ANS-ability of a test to ID those without the DX
Prevalence - ANS-is the number of existing Dx cases during a period of time
= incidence x duration
overall = TP + FN/N
incidence - ANS-number of NEW cases that develop over a period of time
Odds ratio - ANS-a measure of association between a dependent and independent
variable mean, median, and mode
negative skew - ANS-mean is LOWER than median
Positive skew - ANS-mean is HIGHER than median
descriptive research - ANS-do NOT determine a relationship
qualitative research
case report/ study (novel dx)
Correlation/ecological studies
, Analytic research - ANS-experimental- cause can be found (RTCs)
observational- no cause-only association (quasi-experimental, cohort study, case-
control study, cross-sectional study)
nominal variables - ANS-no order ie gender, race etc
Ordinal scale - ANS-a scale of measurement in which the measurement categories form
a rank order along a continuum ie stage 1 cancer
numerical discrete - ANS-data with numbers (number of clinic visits), no set number
numerical continuous - ANS-on a continuum
ex. height, weight, time
Standard deviation - ANS-indicates the dispersion of data about the mean (average)
68% of observations lie within the range 1 SD of mean
32% of observations lie outside the range (rang = mean +/- 1 SD)
95% lie within +/- 2 SD of mean
P values - ANS-P< or equal to 0.05 is significant
the lower the P value the higher the statistical significance of the results
nasogastric tube - ANS-tube inserted through the nose into the stomach
less than 4 weeks
x-ray to make sure in place
Nasoduodenal/Nasojejunal - ANS-nose to the small intestines
less than 4 weeks
x-ray to make sure in place
Gastrostomy/Jejunostomy - ANS-surgically placed directly into the stomach or jejunum
used longer than NG tubes
used if pt cannot have a tube through mouth or throat or they vomit a lot
surgically placed
Percutaneous endoscopic gastrostomy/jejunostomy (PEG/PEJ) - ANS-fed through
mouth to stomach or jejunum can last months to years
complications: gastric content leakage and skin irritation, aspiration (PEG), bleeding or
bowel perforation (PEJ)
Endo placed
G tubes - ANS-prone to leakage, skin irritation, nausea, vomiting, and bloating
J tubes - ANS-increase dirrhea
no bolus feeds- risk of aspiration
