Transcript Association & Causation

Association
&
Causation
Association
• Ms Ashvarya Rai is associated with Mr
Bacchan
• In Epidemiology association refers to a link
between 2 or more factors
• Measures of Association:
Relative Risk or Risk Ratio RR
Risk Difference ( Attributable Risk) RD
Odds Ratio OR ( show Apple)
Causation
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Question- Egg or Hen first?
Temporality- Cause precede effect
Strength of Association
Dose response
Specificity
Biological Plausability
Consistency
Experimental Evidence
Causes in Scripture
Bhagwat Geeta
• Panchaitaani mahaabaaho kaaranaani nibodha me;
• Saankhye kritaante proktaani siddhaye sarvakarmanaam.
• Learn from Me, O mighty-armed Arjuna, these five causes, as
declared in the Sankhya system for the accomplishment of all
actions!
• Adhishthaanam tathaa kartaa karanam cha prithagvidham;
• Vividhaashcha prithakcheshtaa daivam chaivaatra panchamam.
• The body, the doer, the various senses, the different functions of
various sorts, and the presiding Deity, also, the fifth,
• Shareeravaangmanobhiryat karma praarabhate narah;
• Nyaayyam vaa vipareetam vaa panchaite tasya hetavah.
Whatever action a man performs by his body, speech and mind,
whether right or the reverse, these five are its causes.
Chapter 18; Slokes 13,14,15
Causality
• Always a constellation of component
causes
• Nothing is caused by a single cause
• Sufficient cause: A set of minimal
conditions or events needed to cause the
onset of disease
• Rothman’s Causal Pie model
Confounding
• Confundere (Latin)- to confuse ( Bible)
• It is a mixing of effects due to a third factor
in the study – Pati, patni & vo draw
• A factor is a confounder if:
– Associated with exposure in nondiseased
– Associated with disease in unexposed( prior
knowledge)
– Not an intermediate in pathways
– Not a surrogate for an exposure