D3 - Case Series & Cross-sectional Studies, Cohort Studies

Question 1

limitations of case reports and case series

Answer 1

lack of a denominator for calculating disease incidence

lack of a comparison group

select study populations (may not reflect general pop)

sampling variation

Question 2

case report

Answer 2

describe the experiences of a single person

Question 3

case series

Answer 3

describe the experiences of a group of people

Question 4

5 factors used to assess causal inference in clinical research studies

Answer 4

1) randomized evidence
2) strong associations
3) temporal relationship between exposure and outcome
4) exposure or dose varying response
5) biological plausibility

Question 5

what do case reports and case series rely on, to make the case for causation?

Answer 5

almost exclusively rely on biological plausibility

Question 6

cross-sectional study

Answer 6

type of observational study design in which the exposure and the outcome are assessed simultaneously

Question 7

cohort study

Answer 7

type of observational study that determines the incidence of a disease/outcome among diff exposure groups

Question 8

what does the term “exposure” mean?

Answer 8

any characteristic that may explain or predict a disease or outcome

Question 9

key things to consider to have good internal validity

Answer 9

accuracy, repeatability (precision), consistency, timing

Question 10

“accuracy” means..

Answer 10

how well a measurement reflects the true value of a characteristic

Question 11

repeatability/precision

Answer 11

how well a measurement returns the same result when performed successively

Question 12

retrospective study

Answer 12

study that is performed after all of the data have been collected

Question 13

prospective study

Answer 13

collect original data for the specific purpose of addressing a particular study question

Question 14

advantages of cohort studies

Answer 14

can often discern temporal relationship b/n exposure and outcome

can study multiple outcomes

Question 15

disadvantages of cohort studies

Answer 15

can’t prove causation b/c there may be confounding variables

inefficient design for rare diseases and diseases w/ a long latency period

Question 16

Why are cohort studies important in the pharmaceutical world?

Answer 16

can assess clinically important outcomes and unintended side effects of medications in REAL world settings

can evaluate risks/benefits of medications in real settings

Question 17

equation for relative risk

Answer 17

relative risk = incidence (exposed cohort)/incidence (unexposed cohort)

Question 18

equation for attributable risk

Answer 18

incidence (exposed cohort) - incidence (unexposed cohort)

Question 19

equation for population attributable risk

Answer 19

population attributable risk = incidence (total) - incidence (unexposed cohort)