# Study sets matching "biostats"

T/F? In a normal standard distrubtion,…

T/F? In a left skewed distribution, the…

T/F? In a left skewed distribution, the…

T/F? In a normal distribution curve, th…

T

F.

T

T

T/F? In a normal standard distrubtion,…

T

T/F? In a left skewed distribution, the…

F.

probability=

4 steps of hypothesis testing

null hypothesis

random sampling variation

chance

1. making hypothesis... 2. set criteria for decision... 3. gather da…

there is no difference between your sample and the population…

all observed differences are due to chance

probability=

chance

4 steps of hypothesis testing

1. making hypothesis... 2. set criteria for decision... 3. gather da…

A contingency table is widely used to d…

what is the R code to build a contingen…

risk difference is defined as?

NNT or NNH can or cannot contain a deci…

the association between 2 categorical variables

table(data~independent,data~outcome)

a measure of the difference between two proportions... (a/(a+b))-…

cannot (don't have half a person)... round UP

A contingency table is widely used to d…

the association between 2 categorical variables

what is the R code to build a contingen…

table(data~independent,data~outcome)

Hypothesis

Null hypothesis

Alternative hypothesis

Conditions

'a testable prediction drawn from a theory'

'the hypothesis has no effect (eg: the thing you're trying to…

'the hypothesis is correct and has an effect'

'total number of experimental groups in study'

Hypothesis

'a testable prediction drawn from a theory'

Null hypothesis

'the hypothesis has no effect (eg: the thing you're trying to…

Standard deviation

Prevalence

Incidence

Crude (Overall) Mortality Rate (CMR)

Used for symmetric measured data

# of ALL cases of a particular disease in a population... # case…

# of NEW cases of a disease in a population... # of new cases in…

# of deaths/ total population size... Measures the overall death…

Standard deviation

Used for symmetric measured data

Prevalence

# of ALL cases of a particular disease in a population... # case…

Nominal data

Ordinal data

kinds of data in nonparametric tests

Types of tests associated with ordinal…

Comparing modes between groups

comparing medians between groups

Nominal and Ordinal

Mann-whitney U test... Wilcoxan Signed Rank test ... Kruskai wallis…

Nominal data

Comparing modes between groups

Ordinal data

comparing medians between groups

Cross sectional study

Case- Control Study

Cohort Study

Phase 1

Data from a group of people to assess the frequency of a disea…

Compares a group with a disease to a group without the disease…

Compares a group with a given exposure or risk factor to a gro…

Small # of healty volunteers- is it safe?

Cross sectional study

Data from a group of people to assess the frequency of a disea…

Case- Control Study

Compares a group with a disease to a group without the disease…

When can the mean be used?

What type of data can the mean be used…

Is the mean sensitive to outlying value…

When should the median be used?

when data is not skewed

continuous data

yes

when data is skewed

When can the mean be used?

when data is not skewed

What type of data can the mean be used…

continuous data

Sensitivity

Specificity

PPV

NPV

probability that a test detects dz when dz is present... proport…

- true-negative rate... - probability that a test indicates no di…

probability that the person actually has the dz when given a p…

- proportion of negative test results that are TN... - probabilit…

Sensitivity

probability that a test detects dz when dz is present... proport…

Specificity

- true-negative rate... - probability that a test indicates no di…

cross sectional study

cross sectional study

case control study

case control study

collets data form a group of people to assess frequency of dis…

for disease prevlanece

compares a group of people with disease to a group witout dise…

to calcualte odds ratio

cross sectional study

collets data form a group of people to assess frequency of dis…

cross sectional study

for disease prevlanece

Deviation score

nominal data

ordinal data

interval data

D=X-x... Distance a number is from the mean

data are placed in qualitative groups... ex. based on description…

data are placed in ranking orders ... ex. 1st, 2nd, 3rd ... DOESNOT…

data are in a meaningful order

**without**an absolute zero... ofte…Deviation score

D=X-x... Distance a number is from the mean

nominal data

data are placed in qualitative groups... ex. based on description…

mean

population mean

sample mean

variance

the sum of all the values of a population or sample, divided b…

the average squared deviation from the mean

mean

the sum of all the values of a population or sample, divided b…

population mean

Cross Sectional Study... (observational)

Cross Sectional Study measures

Case Control Study... (observational and r…

Case Control Study measures...

collects data from group of people to assess frequency of dise…

disease prevalence... shows risk factor association with disease,…

compares a group of people with disease to a group without dis…

odds ratio... Ex: patients with COPD have higher odds of a histor…

Cross Sectional Study... (observational)

collects data from group of people to assess frequency of dise…

Cross Sectional Study measures

disease prevalence... shows risk factor association with disease,…

nominal

ordinal

discrete/discontinuous

continuous

qualitative... -gender, zip code, hair color, ethnic group

qualitative... -ordered set of relationships

quantitative... -must be whole integers ... -vital statistics such a…

quantitative... -age, height, weight, serum cholesterol, etc; dat…

nominal

qualitative... -gender, zip code, hair color, ethnic group

ordinal

qualitative... -ordered set of relationships

95% CI

Relative risk/Risk ratio (RR)... Probabil…

Number needed to treat (NNT)

Odds ratio (OR)... Represents that probab…

-When 95% for estimated DIFFERENCE between groups (or within t…

-Probability of an unfavorable event occurring in the tx group…

NNT = 100 / % ARR... MUST ALWAYS around up this number! (e.g. 3.0…

-ratio of two odds, or the ratio of the odds of an event occur…

95% CI

-When 95% for estimated DIFFERENCE between groups (or within t…

Relative risk/Risk ratio (RR)... Probabil…

-Probability of an unfavorable event occurring in the tx group…

case control

increasing sample size will

Cohort Study

Risk difference

subjects enrolled based on disease status, one gorup with dise…

NARROW the confidence interval

subjects enrolled based on EXPOSURE status.

the risk difference between two groups... risk in exposed- risk i…

case control

subjects enrolled based on disease status, one gorup with dise…

increasing sample size will

NARROW the confidence interval

simple random sampling

systemic sampling

stratified sampling

cluster sampling

each individual has equal chance of being selected

select at regular intervals through ordered list... -pick random…

separate pop into strata based on a characteristic... randomly s…

pop already in strata... -randomly select groups of strata

simple random sampling

each individual has equal chance of being selected

systemic sampling

select at regular intervals through ordered list... -pick random…

Scientific Method

Descriptive Statistics is also called

Descriptive Statistics

Statistical Inference is also called

Testing and eliminating hypotheses whose predictions are incon…

Exploratory Data Analysis (EDA)

Organization and summarization of data; graphical display to v…

Confirmatory Data Analysis (CDA)

Scientific Method

Testing and eliminating hypotheses whose predictions are incon…

Descriptive Statistics is also called

Exploratory Data Analysis (EDA)