Biostatistics for Dentisrty

Question 1

Qualitative data is

Answer 1

discrete

Question 2

Sensitive to extreme values

Answer 2

Means

Question 3

Less sensitive to extreme values

Answer 3

Median

Question 4

Measure of how much the individual data points vary around the mean

Answer 4

SD

Question 5

Count of a given outcome or in each category

Answer 5

Frequency

Question 6

count of a given outcome per hundred showing the proportion of each category out of the total

Answer 6

percentage

Question 7

As X increases, Y increase has what type of linear value

Answer 7

postive

Question 8

As X increases, Y decrease has what type of linear value

Answer 8

negative

Question 9

What value can lie between -1 and +1

Answer 9

correlation coefficient

Question 10

What is the same for correlation coefficient

Answer 10

r

Question 11

The closer (r) is to -1 or +1 means what

Answer 11

strong correlation

Question 12

The fraction of variation in Y explained by X

Answer 12

square of correlation

Question 13

The (lower/higher) the r squared better fit to the regression line

Answer 13

higher

Question 14

Usually states that there is NO difference between two groups being compared

Answer 14

Null hypothesis

Question 15

States that there is no effect of a product or intervention

Answer 15

Null hypothesis

Question 16

Hypothesis testing that is testing if there is no difference

Answer 16

Non-directional

Question 17

Hypothesis testing that is comparing cases and controlled

Answer 17

directional

Question 18

In this type of hystohesis testing the mean is the key data point, not the individual

Answer 18

Non-directional

Question 19

In non-directional hypothesis testing what is the used

Answer 19

mean

Question 20

Rejecting the null hypothesis that is actually true about the population is what type of error

Answer 20

Type I error

Question 21

Type II error is related to

Answer 21

Power

Question 22

The level of statistical significance is described as

Answer 22

alpha

Question 23

alpha is commonly set at

Answer 23

0.05

Question 24

The maximum of incorrectly rejecting the null hypothesis when it is actually true

Answer 24

alpha

Question 25

Probability of making a type II error

Answer 25

Beta

Question 26

Failing to reject the null hypothesis that is actually false in the population

Answer 26

Type II error

Question 27

The probability of a type II error is described as

Answer 27

beta

Question 28

How is power calculated

Answer 28

1-beta

Question 29

Is related to the sample size used in the study

Answer 29

Power

Question 30

Is the probability, assuming that the null hypothesis is true, of seeing effect ad extreme or more extreme than by chance

Answer 30

P-Value

Question 31

Reject the null hypothesis if the p-value is what to alpha

Answer 31

less than or equal to

Question 32

Fail to reject the null hypothesis if the p-value is what to alpha

Answer 32

greater than

Question 33

The range of values about the sample statistic that we are confident that the true population parameter lies

Answer 33

confidence intervals

Question 34

Statistical test that can be used to determine whether the mean value of continuous outcome variable differs significantly between two independent groups

Answer 34

T-test

Question 35

Test that cannot be used for nominal data

Answer 35

T-Test

Question 36

Test that is used with numerical data

Answer 36

T-Test

Question 37

Test that compares two means

Answer 37

T-Test

Question 38

Assumes a approximate normal distribution of the variable of interest in the groups being compared

Answer 38

T-Test

Question 39

Used with yes or no answers

Answer 39

Chi-squared test

Question 40

Used with categorical data

Answer 40

Chi-squared test

Question 41

Can be used to compare the proportion of subjects in each of two groups who have dichotomous outcome

Answer 41

Chi-squared test

Question 42

Used when null hypothesis is "there is no difference . . ." vs. "there is a difference"

Answer 42

Chi-squared test

Question 43

Used when comparing two or more means

Answer 43

ANOVA

Question 44

Uses F-statistic

Answer 44

ANOVA

Question 45

if we fail to reject the null hypothesis in ANOVA means that all groups are

Answer 45

Equal

Question 46

Analysis of variance

Answer 46

ANOVA

Question 47

Probability that chance is responsible of an observed difference

Answer 47

statistical significance

Question 48

Are the findings important from a clinical standpoint?

Answer 48

Clinical significance

Question 49

Does a P -value say anything about clinical relevance or quality of study

Answer 49

No

Question 50

Do statistics tell us about causality

Answer 50

NO

Question 51

Systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposures effect on a disease

Answer 51

Bias

Question 52

Systematic error in selecting subjects into one or more of the study groups based on their status

Answer 52

selection bias

Question 53

Errors in procedures for gathering relevant information

Answer 53

information bias

Question 54

situation in wich a non-causal association between a given exposure and an outcome is observed as a result of the influence of a third variable

Answer 54

confounding

Question 55

Can lead to conclusions a causal relationship when in fact there is none

Answer 55

confounding

Question 56

confounding is not

Answer 56

all or none