Association/Causation

Question 1

Koch’s Postulates (Deterministic)

Answer 1

-agents must be present in every case
-agent should not occur in any other disease
-agent should be able to be isolated and induce disease in a susceptible disease-free animal

based on anthrax and TB

Question 2

Hill’s Causal Criteria

Answer 2

Question 3

strength of association

Answer 3

relative risk, attributable risk, odds ratio

Question 4

consistency

Answer 4

repeated observation of the association in different populations and circumstances

Question 5

specificity

Answer 5

risk factor associated with single outcome but this is outdated and useless so forget about it

Question 6

Temporality

Answer 6

risk factor must precede outcome (only determined in prospective studies)

Question 7

Biologic Gradient

Answer 7

dose-response relationship

Question 8

Plausibility

Answer 8

does it make sense with current knowledge? (overlap with coherence)

Question 9

Coherence

Answer 9

does it make sense with current knowledge? (overlap with plausibility)

Question 10

Experimental Evidence

Answer 10

data from controlled experimental studies supporting the relationship

Question 11

Analogy

Answer 11

comparability to an established causal relationships (ex: all the differed prion diseases)

Question 12

Rothman’s Causal Pies

Answer 12

exposure is necessary only if it always precedes the disease, but not necessarily sufficient

Question 13

If your odds ratio CI includes 1.0, is it statistically significant?

Answer 13

no!

Question 14

Can a single study indicate causation?

Answer 14

nope, just association