Keywords: 因果推論, Time-varying, G-formula, IP weighting, Doubly robust estimation
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・G-methods for time-fixed treatments本日の内容・The g-formula for time-varying treatments・IP weighting for time-varying treatments・A doubly robust estimator for time-varyingtreatments
Stratificationeffect measure modification (-)effect measure modification (+)Mantel-Haenszel method別々にオッズ比を報告
Why model?effect measure modification (-)effect measure modification (+)別々にオッズ比を報告(1つの効果を報告できない)g-methods
g-formulaA=1を代入A=0を代入
IP weightingmarginal structural model
Conditional or Marginal?outcome regressionsaturated parametricstratificationg-formulaIP weightingg-estimationoralgebraically equivalent
Time-varying treatmentg-methods
前提・本章ではidentifiability conditions(sequentialexchangeability, positivity, and consistency)のviolationがないものとする。・static treatment strategies (always treat vs. never treat)の効果を推定する。
g-formula (weighted average)・time-fixed treatment (A1の反実アウトカム)・time-varying treatment
g-formula (weighted average)
g-formula (simulation)のシミュレーションと
g-formulaの注意点・DAGに基づいたcovariates L1をモデルに含める・static sequential exchangeabilityが成立すればstatictreatment strategyの効果はidentify可能
g-formulaの一般化・static treatment strategy・dynamic treatment strategylinear regression logistic regression
IP weighting (weights)・nonstabilized IP weights・ stabilized IP weights
IP weighting (non-stabilized)
Stabilized weightsnon-stabilized weights: stabilized weights:Lと独立であればよい Lと独立であればよい
IP weighting (stabilized)
IP weightingの一般化・nonstabilized IP weights・ stabilized IP weightslogistic regressionlogistic regression(misspecifiedでも可)
Marginal Structural Model・2K > Nのときは推定できない・marginal structural mean modelstabilized IP weightsを使って推定misspecified??
Effect Measure Modification・baseline variable VによるEMMがある場合、marginalstructural modelは以下の通り(parametric)stabilized IP weightsを使って推定Vに入れて良いのはbaseline variableだけ
Doubly Robust Estimator・g-formula・ IP weighting
1.Doubly Robust (time-fixed)2.3. A=1とA=0でそれぞれを推定を推定,をLについて標準化
1.Doubly Robust (time-varying)2.3.を推定からパラメータを求める。を求めておくを推定し、Aの値に応じた を求める。これを繰り返して を求める。always treat
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