Evaluative Dentistry: Biostatistics 낱말 카드

What allows us to understand information and make clinical decisions based on data?

Statistics

What describes the average of data?

Mean

What describes the middle point of data?

Median

Is the mean or median more sensitive to extreme values?

Mean

What describes the most frequently occurring value in data?

Mode

What describes the measure of how much the individual data points vary around the mean?

Standard deviation

What describes the count of a given outcome?

Frequency

What describes the count of a given outcome per hundred which shows the proportion of each category out of the total?

Percentage

What type of data do bar charts show?

Categorical

What type of data do histograms show?

Quantitative

What describes the linear relationship between an independent variable (X) and a dependent variable (Y)?

Correlation

What can the correlation coefficient (r) lie between?

-1 and +1

What type of correlation increases Y as X increases?

Positive

What type of correlation decreases Y as X increases?

Negative

The closer (r) is to +1 or -1, the stronger or weaker the relationship?

Stronger

What describes the fraction of variation in Y explained by X?

Square of correlation (r^2)

The higher the r^2 the better the fit of the ____________.

Regression line

What describes an explanation for certain observations?

Hypothesis

What is H₀?

Test hypothesis

The test hypothesis usually states that there is ___________ between two groups being compared or ___________ of a product or intervetion.

No difference; no effect

What decribes the hypothesis researchers think is the "truth"?

Ha

Ha usually states that there is _________ between two groups being compared or an effect of a product or intervention.

A difference

What describes rejecting the null hypothesis that is actually true in the population?

Type I error

What describes the level of statistical significance?

alpha

What describes failing to reject (accept) the null hypothesis that is actually false in the population?

Type II error

What describes the probability of a type II error?

beta

What is calculated as 1-beta and is related to the sample size used in the study?

Power

What describes the probability, assuming the null hypothesis is true, of seeing an effect as extreme or more extreme than that in the study by chance?

P-value

You reject or fail to reject the null hypothesis if P-value is < or = alpha?

Reject

You reject or fail to reject the null hypothesis if P-value is > alpha?

Fail to reject

What describes a range of values about a sample statistic that we are confident that the true population parameter lies?

Confidence intervals

What do researchers commonly set the confidence interval at?

95%

What is a statistical test that can be used to determine whether the mean value of a continuous outcome variable differs significantly between two independent groups?

t-test

t-test assumes approximate __________ distribution of the variable of interest in the groups being compared.

Normal

What describes a t-test that can be used when the outcome variable of interest is only being examined in one group?

One sample

What describes a t-test that can be used when subjects are matched in pairs and their outcomes are compared within each matched pair?

Matched pair

What can be used to compare the proportion of subjects in each of two groups who have a dichotomous outcome?

Chi square test

What is a statistical method that allows for comparison of several population means?

ANOVA (analysis of variance)

What statistic is used in ANOVA?

F-statistic

What says nothing about clinical relevance or quality of the study?

P-value

A limitation of statistical inference is that statistics do not tell you about _________.

Causality

What describes the systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposure's effect on disease?

Bias

What describes a systematic error in selecting subjects into one or more of the study groups, such as cases and controls, or exposed and unexposed?

Selection bias

What describes errors in procedures for gathering relevant information?

Information bias

Situation in which a non-causal association between a given exposure and an outcome is observed as a result of an influence of a third variable usually termed a __________.

Confounder