Biostatistics Flashcards

1
Q

Branch of statistics that summarizes information about a group based on the actual data collected

A

Descriptive

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2
Q

Branch of statistics where conclusions are prepared based on the data collected, with predictions made that go beyond the sample analyzed but are generally related to different but related situations

A

Inferential

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3
Q

number that describes the population

A

Parameter

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4
Q

number that describes the sample

A

Statistic

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5
Q

reflects reproducibility or true exactness

A

Precision

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6
Q

reflects closeness to the true value

A

Accuracy

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7
Q

characteristic that varies between different individuals (gender, blood type)

A

Between-subject variable

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8
Q

characteristic of an individual that varies with time (blood pressure, heart rate)

A

Within-subject variable

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9
Q

Data type involving separate, indivisible categories

A

Discrete

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10
Q

Data type involving infinite number of possible values that fit between any two adjacent values

A

Continuous

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11
Q

Scale of measurement: Names or classification data, no order, arbitrary labels

A

Nominal

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12
Q

Scale of measurement: Ordered data, ranks
Groups in sequence (one is better than the other)
Comparative quality or rank order

A

Ordinal

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13
Q

Scale of measurement: Ordered categories with all intervals equal
Categories are randomly assigned
Exact different among groups (how much better)
Quantitative, mean and standard deviation

A

Interval

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14
Q

Scale of measurement: Ordered categories with a fixed absolute zero
Interval with TRUE zero (real difference)

A

Ratio

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15
Q

Skew where left tail is longer; mass of the distribution is concentrated on the right of the curve

A

Negative skew

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16
Q

Skew where right tail is longer; mass of the distribution is concentrated on the left of the curve

A

Positive skew

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17
Q

Peak sharpness where there is a normal distribution

A

Mesokurtic

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18
Q

Peak sharpness where peakedness is greater than normal distribution

A

Leptokurtic

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19
Q

Peak sharpness where peakedness is less than normal distribution

A

Platykurtic

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20
Q

Percentage of data points exist that within 1 standard deviation from the mean

A

0.68

21
Q

Percentage of data points exist that within 2 standard deviations from the mean

A

0.95

22
Q

Percentage of data points exist that within 3 standard deviations from the mean

A

0.99

23
Q

How to calculate joint probability of two independent events

A

P1 x P2

24
Q

How to calculate joint probability of two mutually exclusive events

A

P1 + P2

25
Q

How to calculate joint probability of non-mutually exclusive events

A

(P1 + P2) - (P1 x P2)

26
Q

Do larger sample sizes have wider or narrower confidence intervals?

A

Narrower

27
Q

Z-score used for 90% confidence interval

A

1.645 ~ 1.5

28
Q

Z-score used for 95% confidence interval

A

1.96 ~ 2.0

29
Q

Z-score used for 99% confidence interval

A

2.576 ~ 2.5

30
Q

Equation to calculate confidence interval

A

Mean +/- Z * (stand. dev. / square root n)

31
Q

Equation for standard error of the mean

A

Standard deviation / square root of sample size

32
Q

Statistical test used on 2 interval groups (e.g. height and weight) to show a linear relationship

A

Pearson correlation

33
Q

Statistical test used on 2 nominal groups (e.g. single vs married)

A

Chi-squared

34
Q

Statistic test used for 1 interval and 1 nominal group (2 groups only)
E.g. blood pressure by gender

A

t-test

35
Q

Statistic test used for 2 groups (1 interval and 1 nominal) that are linked data pairs
E.g. blood pressure before and after NBME

A

Matched pairs t-test

36
Q

Statistical test used for 2 or more groups (at least 1 nominal and 1 interval)
E.g. pain improvement by two drugs in two age groups

A

One-way ANOVA

37
Q

Statistical test used to 2 or more groups, 2 nominal variables
E.g. blood pressure in men and women from US and Canada

A

Two-way ANOVA

38
Q

Type of error involving incorrect rejection of a true null hypothesis (false positive)
Chance is alpha value (P value)

A

Type I error

39
Q

Chance of type I error is given by this

A

Alpha value (P value)

40
Q

Type of error involving incorrectly retain a null hypothesis (fail to reject) a false negative
Probability is beta (1 - power)

A

Type II error

41
Q

Chance of type II error is given by this

A

Beta (= 1 - Power)

42
Q

likelihood a study will detect an effect then there is one to be detected

A

Statistical power

43
Q

Statistical power increases as this type of error decreases

A

Type II

44
Q

5 steps in evidence-based medicine

A

Ask, Acquire, Appraise, Apply, Audit

45
Q

PICO(T) is used for this step in evidence-based medicine

A

Ask: convert information need into an answerable clinical question

46
Q

In evidence-based medicine, P in PICO describes this

A

Problem or population (patient)

47
Q

In evidence-based medicine, I in PICO describes this

A

Intervention

48
Q

In evidence-based medicine, C in PICO describes this

A

Comparison

49
Q

In evidence-based medicine, O in PICO describes this

A

Outcome