EBM Terms

Question 1

Happens when process for randomization is not ideal

Answer 1

Randomization Bias

Question 2

Happens when recruiters of participants have knowledge of the next stage in a trial

Answer 2

Selection Bias

Question 3

Happens when there is an undeniable difference between how groups are treated

Answer 3

Performance bias

Question 4

Happens when there is a difference between groups due to participants leaving the trial

Answer 4

Attrition or loss of participants bias

Question 5

Happens when groups are assessed differently

Answer 5

Detection Bias

Question 6

happens when interpretation of results are impacted due to experimenter having knowledge of which intervention a participant receives

Answer 6

Ascertainment bias

Question 7

Happens when there is bias due to the availability of a publication or if publication chooses to publish findings in favour of their hypothesis

Answer 7

publication bias

Question 8

Happens due to a tendency for publications with favourable results to be published in the English language

Answer 8

Language bias

Question 9

A measure of how well a study is conducted and how accurately its results reflect the study group

Answer 9

Internal Validity

Question 10

The extent to which a study is generalizable to the population

Answer 10

External validity

Question 11

Balanced process of allocating patients equally to each group

Answer 11

Randomization, prevents selection bias

Question 12

Document of a single medical occurrence, usually a rare disease or idiosyncratic reaction

Answer 12

Case Report
- detect rare adverse effects of drugs
- detects potential off-label use
- cost friendly and time efficient

Question 13

Examine relationship between disease/outcome and other variables at the present time

Answer 13

Cross sectional study
- useful to quantify prevalence of a disease or risk factor
- describes PREVALENCE, NOT incidence
- cheap and ethically safe

Prevalence = old + new cases / total population
Incidence rate = all new cases / total population (Cohort)

Question 14

Compare those with similar medical conditions to those who do not but are otherwise nearly identical. Look back retrospectively to see the frequency of exposure to the risk factor in each group

Answer 14

Case Control
- study depends upon history given by subject, RECALL bias can occur

Question 15

Compare those exposed and not exposed to some variable and see what occurs. Observational, descriptive, prospective (sometimes retrospective)

Answer 15

Cohort Study
- can calculate rates of disease (ex Incidence)
- useful for uncommon exposures/common diseases
- examine multiple outcome for a given exposure