Statistics Flashcards

1
Q

What do the bottom and top represent on the box-and-whisker plot?

A

Lower and upper quartile

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2
Q

What type of variable is BMI ?

A

Continuous

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3
Q

How to calculate standard error of the mean?

A

SEM = SD/√n

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4
Q

In statistics population consists of

A

all subjects or objects whose characteristics are being studied

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5
Q

for a negatively skewed data, mean will be

A

mean < median < mode

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6
Q

for a Postively skewed data, mean will be

A

mean > median > mode

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7
Q

Axises of ROC curve

A

Sensitivity/ (1-Specificty)

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8
Q

Standard deviation:

A

Square root of Variance

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9
Q

The ability of a test to correctly identify those who have the disease

A

Sensitivity

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10
Q

The proportion of well people who are correctly classified by the screening test as negative

A

Specificity

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11
Q

The proportion of people with a positive screening test who are diseased.

A

Positive Predictive value (PPV)

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12
Q

The proportion of people with a negative screening test who are well.

A

Negative predictive value (PPV)

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13
Q

Formula of PPV

A

All the positives

TP/TP+FP

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14
Q

Formula of NPV

A

All the Negatives

TN/TN+FN

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15
Q

Formula of sensitivity

A

TP/TP+FN

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16
Q

Formula of Specificity

17
Q

to know the number of occurrences of an event at any given interval.

A

Poisson Distribution

18
Q

What is Variance?

A

measures the degree of spread (dispersion) in a variables value
FORMULA: V= ( SD2)

19
Q

Standard Deviation

A

measure of how spread out the numbers are from the mean

FORMULA: SD = √ Variance

20
Q

Interquartile Range

A

dividing data set into quartiles and getting the midspread or middle 50%

FORMULA : IQR= Q3-Q1

21
Q

Standard error of the mean SEM:

A

is an estimate of how far the sample mean is likely to be from the population mean
FORMULA: SEM = SD/ √n

22
Q

Significant level α

A

is the probability of the study rejecting the null hypothesis, given that the null-hypothesis is true.
Significance level is set at α= 0.05 or 5%

23
Q

Significant P value: Probability value (probability of chance)

A

any number between 0 to 1

the lower the p value the more statistically significant the study is.

24
Q

Low p-value < 0.05 indicates

A

strong evidence against the null hypothesis. So your study can REJECT the null hypothesis.

25
High p- value >0.05 indicates
weak evidence against the null hypothesis. So your study FAILS to REJECT and thus ACCEPTS the null hypothesis.
26
FORMULA of Confidence interval :
CI= Mean +/-multiplier x SEM
27
the value of multiplier for confidence intervals
90% --> 1.65 95% --> 2 98% --> 2.33 99% --> 2.58
28
Which study is most appropriate to assess a prognosis of a disease?
Cohort study
29
Which study is most appropriate to assess the efficacy of a new medication
Randomized clinical trials
30
Which studies Involves analysis of data for a population at one specific point in time?
Cross sectional
31
The hypothesis that researchers try to prove
alternative hypothesis
32
The hypothesis that researchers try to disprove
null hypothesis
33
Which drug trial phase primarily assesses the safety of a drug?
Phase 1
34
What is Evidence based medicine?
use current experimental evidences to treat individual patients
35
Increasing sample size will
decrease type 2 errors and increase power of the results.
36
Which study is most appropriate to assess a diagnostic test?
Cross Sectional Analysis