Bias Sampling

Question 1

what is internal validity affected by

Answer 1

1. chance
2. bias

Question 2

what is chance

Answer 2

random error

Question 3

what is bias

Answer 3

any systematic error in an epidemiology study that results in an incorrect estimate of the association between exposure and risk of disease

Question 4

true or false
there is an unpredictable over or underestimation of the measurement each time

Answer 4

false

Question 5

what are the 2 categories of bias

Answer 5

selection bias
information bias

Question 6

which bias or error is based on who researchers select as study participants

Answer 6

selection bias

Question 7

what are types of selection bias

Answer 7

non-response bias
sampling bias
loss to follow-up bias

Question 8

what type of selection bias is used in prospective cohort studies

Answer 8

non-response vias

Question 9

what type of selection bias is used in case-control studies

Answer 9

sampling bias

Question 10

what is one way sampling bias is avoided

Answer 10

randomization

Question 11

what type of bias occurs when researchers are unable to collect accurate data on exposure or disease status

Answer 11

information bias

Question 12

true or false:
information bias can be due to non-differential misclassification if both study groups are affected equally or differential misclassification if it affects one study group more than the other

Answer 12

true

Question 13

what are 2 types of information bias

Answer 13

interviewer bias
surveillance bias

Question 14

what can cause misclassification

Answer 14

recall bias
observer bias

Question 15

what is the ability of respondents to accurately remember exposure of pet

Answer 15

recall bias

Question 16

what is any kind of systematic discrepancy from the truth during the process of observing and recording information for a study

Answer 16

observer bias

Question 17

what is the target population

Answer 17

entire set of subjects whose characteristics are of interest to the research team

Question 18

what is a sample

Answer 18

subset of individuals in the target population from which researchers will draw their conclusions about the target population, following the process of statistical inference

Question 19

what is used to truly represent the population

Answer 19

method sampling

Question 20

which sampling has each member of the population a known probability of being selected

Answer 20

probability samples

Question 21

what are types of probability sampling methods

Answer 21

random sampling
systematic sampling
stratified sampling
cluster sampling

Question 22

what is the best method of sampling where each individual in the population has an equal chance of being selected

Answer 22

random samplingd

Question 23

which type of random sampling has each subject in a population has an equal chance of being selected

Answer 23

simple random sampling

Question 24

which type of random sampling has the selection a known and equal predefined interval such as select every 4th animal in a herd

Answer 24

systematic random sampling

Question 25

which type of random sampling occurs when the samples are divided into strata and random sample taken from each strata

Answer 25

stratified random sampling

Question 26

what type of random sampling is a probability sample in which each sampling unit is a collection of elements usually within a strata

Answer 26

cluster sampling

Question 27

which sampling techniques are often used in qualitative research where the aim is not to test a hypothesis but to develop an initial understanding of a population

Answer 27

non-probability sampling

Question 28

what is the purpose of non-probability sampling

Answer 28

produces biased population estimates as sampling is non-random

Question 29

true or false nonrandom sampling is common in clinical research for practicality and leads to unbiased population estimates

Answer 29

false it leads to biased population estimates

Question 30

what is qualitative research, to gain detailed knowledge about a specific phenomenon rather than make statistical interferences

Answer 30

purposive sampling

Question 31

how does purposive sampling work

Answer 31

the researcher chooses a sample most useful to the purposed of the research-must have clear criteria and rationale for inclusion

Question 32

what is a confounder

Answer 32

variable in a study that distorts the true relationship between an exposure and an outcome, so it seems that the exposure an the outcome are either more or less associated than they really are

Question 33

what does confounding usually occur

Answer 33

usually occurs when the 2 groups compared are not similar

Question 34

what is used in the design stage (before study is conducted)

Answer 34

randomisation matching restriction

Question 35

what is a part of the analysis stage

Answer 35

stratification multivariate analysis

Question 36

what is the only way to equalize all confounders

Answer 36

randomisation (chance)

Question 37

what is sufficient sample size

Answer 37

randomization is likely to control both known and unknown confounders

Question 38

what is restriction

Answer 38

the study to a subgroup that is homogenous for particular characteristics such as age

Question 39

true or false once data is collected, confounders must be known in order to control for them at this stage for the study

Answer 39

true

Question 40

what are two controllings for confounders

Answer 40

stratification multivariate analysis

Question 41

what is the evaluate association within subgroups of the confounding variable

Answer 41

stratification

Question 42

what can be used to control the confounder

Answer 42

stratify the confounding variable by degree of urbanisation calculation to determine the level of confounding by the confounding variable

Question 43

what is the technique that takes into account many variable at the same time that may confound the effect of exposure

Answer 43

multivariate analysis