Statistics

Question 1

Formula for NNT

Answer 1

1/(absolute risk reduction)

Question 1

Number of patients to treat to prevent a bad outcome

Answer 1

Number needed to treat (NNT)

Question 2

Meta-analysis can help to (inc/dec) power (detecting whether or not a difference is significant between two groups) of a study

Answer 2

Increase

Question 3

Analysis looking at correlation between one or more independent variables (e.g., exposures, risk factors), which can be quantitative or qualitative, and a quantitative dependent variable (e.g., lab values)

Answer 3

Regression analysis

Question 4

Analysis that quantitatively combines and analyzes the results of several studies to conduct an analysis with higher statistical power than that of individual studies

Answer 4

Meta-analysis

Question 5

Measure that shows how frequently a specific event (i.e., initiation of drug abuse) occurs in one group relative to how frequently it occurs in another group over time

Answer 5

Hazards ratio

Question 6

Measures strength of association between 2 categorical variables. For example, to determine the association between a risk factor (e.g., poor socioeconomic status) with an outcome (e.g., early start of taking drugs.

Answer 6

Relative Risk

Question 7

Needed to harm equation

Answer 7

1/ Attributable Risk =
1/ [(risk of event with new factor like med) - (risk of event in control group)

Question 8

Researcher’s subconscious influence on the subjects of a research study

Answer 8

Expectancy bias

Question 9

Selection bias that can occur by recruiting hospitalized patients as the control group

Answer 9

Berkson’s bias

Question 10

Measure used for case control studies

Answer 10

Odds ratio

Question 11

Case control studies are almost always prospective/retrospective

Answer 11

retrospective

Question 12

Increasing power of a study allows for increased possibility to reject a _____ if it is truly false

Answer 12

Null hypothesis

Question 13

Lifetime prevalence of mental disorders in adolescents as found in the National Comorbidity Survey – Adolescent Supplement is around __%

Answer 13

50%

Question 14

The occurrence of new cases over a specified period of time in a population

Answer 14

Incidence

Question 15

The extent to which one diagnosis is replicated by multiple physicians on one patient is best described by ______

Answer 15

Precision

Question 16

Rate that refers to the proportion of people with a particular condition who end up dying from that condition.

Answer 16

Case fatality rate
2% of pts develop arrthymia, 40% die from the arrythmia. 40% is the case fatality rate

Question 17

ID the rate type.

Proportion of people dying from a particular disease in the general population.

Answer 17

Mortality Rate

Question 18

The degree of relationship between two constructs that is theoretically present, and is found to be related in the study (using two measures for anxiety produce similar results, for example)

Answer 18

Convergent validity

Question 19

A type of observer-expectancy bias that occurs when the expectations of the investigators affect the outcome of the study

Answer 19

Pygmalion effect

Question 20

A statistical method that includes all patients, including those who dropped out of the study and analyzes them based on their assigned group

Answer 20

Intention to treat analyses

Question 21

A major concern in studies that experience unequal loss of participants from different groups being compared

Answer 21

Attrition bias

Question 22

Bias related to the timing of diagnosis rather than the effectiveness of an intervention

Answer 22

Lead time bias

Question 23

a concern in retrospective studies where participants must recall past behaviors or events

Answer 23

Recall bias