Research Flashcards

Question

Snowball sampling

Answer 1

involves an initial subject who then recommends another subject who meets the study criteria

Answer 2

obtaining a random sample from a population and then stratifying them into subgroups with similar criteria; sample groups are then created by taking a member from each subgroup

Answer 3

inviting participants who are easy to contact

Answer 4

selecting samples after dividing a population into subgroups that do not have any overlap in similarities

Answer 5

selecting participants from a list at random set intervals

Answer 6

Studies a group of patients with a disease and compares them to a historical control group

Answer 7

Studies a single person, group, or situation involving a rare condition

Answer 8

Studies a random sample (cross-section in time) from a target population ○ Easy to administer ○ Cannot prove a cause and effect relationship ○ Measures prevalence

Answer 9

Studies a random sample selected based on presence or absence of disease ○ Samples are placed into either a case group (people who had an exposure) or a control group (people who did not have an exposure) ○ Individuals are observed to see if the predicted outcome occurs ○ Uses odds ratios ○ This study is most impacted by recall bias (change in the risk that participants in a study are able to recall or report information)

Answer 10

Studies a random sample from a healthy, at risk population and follows them over time ○ Identifies new events of disease ○ Prospective cohort studies follow individuals over time ○ Retrospective cohort studies collect information about individuals’ pasts ○ Measures incidence ○ Uses relative risk

Answer 11

Studies non-random sample groups ○ Samples are placed into either one of two control groups or one of two different treatment groups

Answer 12

Studies two randomly assigned sample groups ○ Samples are placed into either a treatment (intervention) or control group

Answer 13

Studies results from two or more published studies ○ A systematic review collects and summarizes data that fits into a specified category ○ A meta-analysis uses statistical methods to analyze the results of all the gathered studies

Answer 14

numeric variables that are obtained by measuring ○ E.g., millimeters

Answer 15

assigned based on a qualitative property, not numeric ○ E.g., hair color

Answer 16

numeric variables that are obtained by taking a count from a set of distinct whole values ○ E.g., number of teeth in a patient’s dentition

Answer 17

variables that are obtained by ordering or ranking ○ E.g., the first, second, or third individual to finish a task

Answer 18

variables that can only take on two possible values or categories ○ E.g., the presence or absence of oral cancer

Answer 19

variable manipulated by the researcher ○ E.g., different types of analgesics

Answer 20

variable measured by the researcher ○ E.g., reported pain level

Answer 21

Intra-examiner reliability Inter-examiner reliability

Answer 22

amount of variability between two or more examiners

Answer 23

amount of variability made by the same examiner on multiple occasions

Answer 24

patient has a disease and the test correctly detects the disease

Answer 25

patient has a disease and the test incorrectly detects no disease

Answer 26

patient does not have a disease and the test incorrectly detects disease

Answer 27

patient does not have a disease and the test correctly detects no disease

Answer 28

measures the accuracy of the test in detecting disease ○ High sensitivity indicates low numbers of false negatives Se = TP / (TP + FN)

Answer 29

measures the accuracy of the test in detecting health ○ High specificity indicates low numbers of false positives Sp = TN / (TN + FP)

Answer 30

probability a test will accurately identify a disease PPV = TP / (TP + FP)

Answer 31

probability a test will accurately identify no disease NPV = TN / (TN + FN)

Answer 32

a higher true positive rate and therefore a higher test accuracy

Answer 33

a higher false positive rate and therefore a lower test accuracy

Answer 34

provides a range of values that a percentage of the population likely falls into ○ For example, if a study on average height in inches has a 95% CI of [63-67], there is a 95% chance that the true average height falls between 63 and 67 inches

Answer 35

measured mathematically using p-values ○ Conventionally, a value lower than an alpha significance level of 0.05 is considered statistically significant and the null hypothesis can be rejected

Answer 36

measured using numbers needed to treat (NNT) ● NNT signifies the total number of patients needed to be treated for one patient to be cured of disease ○ NNT of 1 is the best ○ Only considered if p < 0.05

Answer 37

false positive result ○ Rejecting a null hypothesis that is actually true ○ Probability of making this error is represented by an alpha value which is the p-value for rejecting the null hypothesis ■ P-value: measures probability that the sample data is due to chance, typically is set to 0.05

Answer 38

false negative result ○ Failing to reject a null hypothesis that is actually false ○ Probability of making this error is represented by the beta value which is the statistical power ■ Statistical power: probability of observing an effect

Answer 39

average of values in a data set, affected by outliers

Answer 40

middle score in a data set, least affected by outliers

Answer 41

most frequent value in a data set

Answer 42

○ 95% represents the level of confidence ○ [s,n] represents the standard deviation (s) and the sample size (n) ○ [1.0,500] corresponds with the s and n values of the study ■ Standard deviation (s) = 1.0 and sample size (n) = 500 ○ [1.4-1.6] represents the confidence interval of the data

Answer 43

the study population is chosen from a group that is easy to reach or access

Answer 44

differing rates of responses from relative groups

Answer 45

participants perform differently in a study than if they were not in a study

Answer 46

tendency for people to respond favorably knowing they are receiving treatment

Answer 47

when the outcome of a study biases whether or not to publish the study

Answer 48

values may be extremely high or low to begin, but over time they will regress to an average level

Answer 49

when the study population is not representative of the population of interest

Answer 50

Used to summarize information from individual studies in a meta-analysis ● Width of the horizontal line represents the range of a variable being tested (examples: relative risk, odds ratio) within the confidence interval ● If a confidence interval crosses the vertical line of “no difference” (odds ratio or relative risk of 1), the outcome is not statistically significant

Answer 51

Used to represent numerical data ● Plots values including the median and quartiles, dividing the data set into groups of equal sizes ● Interquartile range: difference between the first (Q1) and third (Q3) quartiles ○ Indicates the extent of dispersion of the middle 50% of the data set

Research Flashcards

(75 cards)