Incidence Conditional Survival Proportion Cumulative Survival Proportion K t k

Incidence conditional survival proportion cumulative

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Incidence Conditional Survival Proportion Cumulative Survival Proportion K t k A k N k CI k S k Cumulative survival proportion over the whole time interval is the product of the conditional survival proportions for every subinterval t k-1 to t k . Censored observations have the same probability of the event after censoring as those remaining under observation.
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[Measure of Association] Incidence Rate (IR) Incidence Rate Ratio (IRR) IR E ¿ IR E + ¿ ¿ IRR = ¿ Range: 0 to ∞ No association: 1 (IRR-1)*100% greater rate of outcome among subjects exposed to exposure. A rate of outcome among exposed subjects is IRR times higher than that of rate among unexposed subjects. Incidence Rate Difference (IRD) E ¿ E + ¿ IE ¿ IRD = IR ¿ synonym: attributable rate Range: −∞ to ∞ This difference reflects the rate of outcome among exposed subjects that can be attributed to the exposure. Cumulative Incidence (CI) Cumulative Incidence Ratio (CIR) CI E ¿ = Pr [ Y = 1 A = 1 ] Pr [ Y = 1 A = 0 ] CI E + ¿ ¿ CIR = ¿ Range: 0 to ∞ No association: 1 Study participants who were Exposed have AA times the CI of Outcome compared to participants who were unexposed over the study periods. Cumulative Incidence Difference (CID) E ¿ E + ¿ CI ¿ CID = CI ¿ Synonym: attributable risk Range: -1 to +1 No association: 0 NNT = 1/CID Odds Ratio Pr [ A = 1 | A = 1 ] / Pr [ Y = 0 A = 1 ] Pr [ Y = 1 | A = 0 ] / Pr [ Y = 0 A = 0 ] Range: 0 to ∞ No association: 1 The odds of A = 1 is OR times that of those that do not have A.
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[Attributable Fraction] Attributable risk percent (AR%) CI E + ¿ × 100 E + ¿ CI E ¿ ¿ CI ¿ AR = ¿ Proportion of disease burden among the exposed caused by exposure Population attributable risk percent CI Total CI E ¿ CI Total = AR × Pr [ A = 1 Y = 1 ] ¿ Proportion of disease burden among total population by exposure
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DAG [The association & Causation] The association flows regardless of the direction of the allows The causation flows the direction of the allow (left to right) [Confounder] Definition of a confounder is: Associated with the exposure (A) in the study base that produce the case Associated with the outcome (Y) in the non-exposed Is not a downstream consequence of exposure or outcome [Collider] A common effect Depicted as two arrows intersecting at a variable Blocks the flow of association [Systematic bias] A structural association between exposure and outcome that does not arise from the causal effect Assume the average causal null hypothesis Incorrect estimate of the effect, if a causal effect Biased estimates are not valid [Mediator] No confounding, no backdoor path [Conditioning] A common cause: blocks the flow of association A common effect: opens the flow of association A consequence of a common effect: opens the flow of association A Mediator: Blocks the flow of association [Control for Confounding] Randomization: known & unknown confounders Restriction, matching: known confounders only IP weighting/ standardization: known confounders only Stratification: known confounders only [Selection bias] Can occur in any types of study (observational & randomized study) By conditioning on the common effect of the exposure and the outcome
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[Confounding] Definition: − Presence of common causes or lack of exchangeability There is confounding when
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