Algebra & Biostatistics

Question 1

Accuracy

Answer 1

How close the average of measured values are to the true value.

• improved by making replicate measurements & taking the average
• assessed by calculating the percent error

Question 2

Precision

Answer 2

How close measured values are to each other. “ Agreement b/w replicate measures”

• improved by careful lab technique &/or using instruments capable of yielding greater precision I.e. More significant figures
• standard deviation is a measure of precision

Question 3

Peta

Answer 3

P

10^15

1E+15

Question 4

Tera

Answer 4

T

10^12

1E+12

Question 5

Giga

Answer 5

G

10^9

1E+09

Question 6

Mega

Answer 6

M

10^6

1,000,000

Question 7

Kilo

Answer 7

k

10^3

1,000

Question 8

Hecto

Answer 8

h

10^2

100

Question 9

Deca

Answer 9

da

10^1

10

Ten

Question 10

Deci

Answer 10

d

10^-1

0.1

Tenth

Question 11

Centi

Answer 11

c

10^-2

0.01

Hundredth

Question 12

Milli

Answer 12

m

10^-3

0.001

Thousandth

Question 13

Micro

Answer 13

u

10^-6

0.0000001

Millionth

Question 14

Nano

Answer 14

n

10^-9

1E-09

Billionth

Question 15

Inferential Statistics

Answer 15

Used to draw conclusions about the data

Trying to reach conclusions that extend beyond the immediate data alone

Are the two groups different?

Question 16

Categorical Variables

Answer 16

• Nominal
• Ordinal
• Dichotomous

Question 17

Continuous Variables

Answer 17

• Interval

- Ratio

Question 18

Nominal Variables

Answer 18

• no intrinsic order
• example: color of shirts.
• No mean or median, but can have a mode.

Question 19

Ordinal Variables

Answer 19

• Have order
• example: scale of 1-5 on how much you like tofu
• has a median and a mode, may have a mean

Question 20

Dichotomous Variables

Answer 20

• only has 2 values

- example: male or female

Question 21

Interval Variables

Answer 21

• numerical value & is measured.
• example: age, height, temperature, years of nursing
• has a mean, median and mode

Question 22

Ratio Variables

Answer 22

• like interval, but value of 0 indicates there is nothing
• can’t go below zero
• example: age, years of nursing, height
• has a mean, median and mode

Question 23

Clinical Trial

Answer 23

Experimental study in which the exposure status (assigned to active drug vs. placebo) is determined by the investigator

Question 24

Randomized Controlled Trial

Answer 24

A special type of clinical trial in which assignment to an exposure is determined purely by chance

Question 25

Cohort Study

Answer 25

Observational study in which subjects with an exposure of interest (i.e. Hypertension) and subject without the exposure are identified and then followed forward in time to determine outcomes PRO- few selectional bias CON- takes a long time

Question 26

Case-Control Study

Answer 26

Observational study that first identifies a group of subjects with a certain disease and a control group without the disease, and then looks to be back in time to find exposure to risk factors for the disease. This type of study is well-suited for rare diseases PRO- results are quick CON- a lot more selectional bias

Question 27

Cross-Sectional Study

Answer 27

Observational study that is done to examine presence or absence of a disease or presence or absence of an exposure at a particular time PRO- large group, quick results CON- unclear if exposure preceded the outcome

Question 28

Bias

Answer 28

Any systematic error in the design or conduct of a study that results in a mistaken estimate of an exposure's effect on risk of disease

Question 29

Selectional Bias

Answer 29

Bias introduced by the way in which participants are chosen for a study

Question 30

Confounding

Answer 30

This occurs when an investigator falsely concludes that a particular exposure is casually related to a disease without adjusting for other factors that are known risk factors for the disease and are associated with the exposure

Question 31

Sensitivity

Answer 31

The ability of the test to identify correctly those who have the disease. It is the number of subjects with a positive test who have disease divided by all subjects who have the disease. A test with high sensitivity has few false negative results

Question 32

Specificity

Answer 32

The ability of the test to identify correctly those who do not have the disease. It is the number of subjects who have a negative test and do not have the disease divided by the number of subjects who do not have the disease. High specificity has few false positives. High specificity low sensitivity Low specificity high sensitivity