Survival-time inverse-probability- weighted regression adjustment

Slides:



Advertisements
Similar presentations
Controlling for Time Dependent Confounding Using Marginal Structural Models in the Case of a Continuous Treatment O Wang 1, T McMullan 2 1 Amgen, Thousand.
Advertisements

Lecture 28 Categorical variables: –Review of slides from lecture 27 (reprint of lecture 27 categorical variables slides with typos corrected) –Practice.
Logit & Probit Regression
Omitted Variable Bias Methods of Economic Investigation Lecture 7 1.
Informative Censoring Addressing Bias in Effect Estimates Due to Study Drop-out Mark van der Laan and Maya Petersen Division of Biostatistics, University.
Nguyen Ngoc Anh Nguyen Ha Trang
CJT 765: Structural Equation Modeling Class 3: Data Screening: Fixing Distributional Problems, Missing Data, Measurement.
1Prof. Dr. Rainer Stachuletz Limited Dependent Variables P(y = 1|x) = G(  0 + x  ) y* =  0 + x  + u, y = max(0,y*)
1. Estimation ESTIMATION.

Inferences About Means of Two Independent Samples Chapter 11 Homework: 1, 2, 3, 4, 6, 7.
Maximum Likelihood We have studied the OLS estimator. It only applies under certain assumptions In particular,  ~ N(0, 2 ) But what if the sampling distribution.
How to deal with missing data: INTRODUCTION
Lecture 14-2 Multinomial logit (Maddala Ch 12.2)
CSE 221: Probabilistic Analysis of Computer Systems Topics covered: Statistical inference.
Generalized Linear Models
Logistic regression for binary response variables.
Marshall University School of Medicine Department of Biochemistry and Microbiology BMS 617 Lecture 12: Multiple and Logistic Regression Marshall University.
GEE and Generalized Linear Mixed Models
Single and Multiple Spell Discrete Time Hazards Models with Parametric and Non-Parametric Corrections for Unobserved Heterogeneity David K. Guilkey.
“Analyzing Health Equity Using Household Survey Data” Owen O’Donnell, Eddy van Doorslaer, Adam Wagstaff and Magnus Lindelow, The World Bank, Washington.
Lecture 8: Generalized Linear Models for Longitudinal Data.
Estimating parameters in a statistical model Likelihood and Maximum likelihood estimation Bayesian point estimates Maximum a posteriori point.
Bayesian Analysis and Applications of A Cure Rate Model.
SUTVA, Assignment Mechanism STA 320 Design and Analysis of Causal Studies Dr. Kari Lock Morgan and Dr. Fan Li Department of Statistical Science Duke University.
Estimating Causal Effects from Large Data Sets Using Propensity Scores Hal V. Barron, MD TICR 5/06.
CS 782 – Machine Learning Lecture 4 Linear Models for Classification  Probabilistic generative models  Probabilistic discriminative models.
When and why to use Logistic Regression?  The response variable has to be binary or ordinal.  Predictors can be continuous, discrete, or combinations.
Logistic and Nonlinear Regression Logistic Regression - Dichotomous Response variable and numeric and/or categorical explanatory variable(s) –Goal: Model.
Propensity Score Matching for Causal Inference: Possibilities, Limitations, and an Example sean f. reardon MAPSS colloquium March 6, 2007.
BIOST 536 Lecture 11 1 Lecture 11 – Additional topics in Logistic Regression C-statistic (“concordance statistic”)  Same as Area under the curve (AUC)
Pro gradu –thesis Tuija Hevonkorpi.  Basic of survival analysis  Weibull model  Frailty models  Accelerated failure time model  Case study.
Chapter 4: Introduction to Predictive Modeling: Regressions
Agresti/Franklin Statistics, 1 of 88  Section 11.4 What Do We Learn from How the Data Vary Around the Regression Line?
Latent regression models. Where does the probability come from? Why isn’t the model deterministic. Each item tests something unique – We are interested.
1 Chapter 4: Introduction to Predictive Modeling: Regressions 4.1 Introduction 4.2 Selecting Regression Inputs 4.3 Optimizing Regression Complexity 4.4.
Qualitative and Limited Dependent Variable Models ECON 6002 Econometrics Memorial University of Newfoundland Adapted from Vera Tabakova’s notes.
Logistic regression (when you have a binary response variable)
Lecture 3 (Chapter 4). Linear Models for Longitudinal Data Linear Regression Model (Review) Ordinary Least Squares (OLS) Maximum Likelihood Estimation.
Week 7: General linear models Overview Questions from last week What are general linear models? Discussion of the 3 articles.
The parametric g-formula and inverse probability weighting
Logistic Regression Logistic Regression - Binary Response variable and numeric and/or categorical explanatory variable(s) –Goal: Model the probability.
1 Borgan and Henderson: Event History Methodology Lancaster, September 2006 Session 8.1: Cohort sampling for the Cox model.
Marshall University School of Medicine Department of Biochemistry and Microbiology BMS 617 Lecture 13: Multiple, Logistic and Proportional Hazards Regression.
Chapter 13 LOGISTIC REGRESSION. Set of independent variables Categorical outcome measure, generally dichotomous.
Heteroscedasticity Chapter 8
Survival time treatment effects
Simple Linear Regression
Inference for Proportions
Sec 9C – Logistic Regression and Propensity scores
M.Sc. in Economics Econometrics Module I
Linear Mixed Models in JMP Pro
The Centre for Longitudinal Studies Missing Data Strategy
Generalized Linear Models
Multiple Imputation Using Stata
Date: Presenter: Ryan Chen
Methods of Economic Investigation Lecture 12
Presenter: Wen-Ching Lan Date: 2018/03/28
Treatment effect: Part 2
OVERVIEW OF LINEAR MODELS
Additional notes on random variables
Bootstrapping Jackknifing
OVERVIEW OF LINEAR MODELS
Additional notes on random variables
Heteroskedasticity.
Counterfactual models Time dependent confounding
Maximum Likelihood We have studied the OLS estimator. It only applies under certain assumptions In particular,  ~ N(0, 2 ) But what if the sampling distribution.
Nazmus Saquib, PhD Head of Research Sulaiman AlRajhi Colleges
Kaplan-Meier survival curves and the log rank test
Limited Dependent Variables
Presentation transcript:

Survival-time inverse-probability- weighted regression adjustment 2017/09/26 Wen-Ching Lan

IPWRA estimators model both the outcome and the treatment to account for the nonrandom treatment assignment. IPWRA uses IPW weights to estimate corrected regression coefficients that are subsequently used to perform regression adjustment.

Survival-time treatment-effects estimators handle two types of missing data. First, only one of the potential outcomes is observed, as is standard in causal inference. Second, the potential outcome for the received treatment may be censored.

Weighted adjusted censoring assumptions The censoring time must be random. The censoring time must be from a known distribution. The distribution of the censoring time cannot vary by treatment level.

Weighted regression adjusted estimators Each observation-level weight is the inverse of the probability of not being censored. The WRA estimators use averages of the predicted mean survival times to estimate treatment-effect parameters.

Inverse-probability-weighted estimators IPW estimators are weighted averages of the observed outcome. The weights correct for missing data due to unobserved potential outcomes and censoring. Each weight is the inverse of the probability that a given value is observed. Observed values that were not likely to be observed have higher weights.

Inverse-probability-weighted regression adjustment estimators IPWRA estimators are averages of treatment-specific predicted conditional means that were made using missingness-adjusted regression parameters. The censored observations can be handled either by weighting under the WAC assumptions to obtain the WAC-IPWRA estimator or by adding a term to the log-likelihood function to obtain the LAC-IPWRA estimator.

There are two methods of accounting for the data lost to censoring: likelihood-adjusted-censoring IPWRA (LAC-IPWRA) Weighted-adjusted-censoring IPWRA (WAC-IPWRA)

Likelihood-adjusted-censoring IPWRA When a censoring model is not specified, stteffects ipwra uses the formulas for the LAC-IPWRA given in Likelihood-adjusted-censoring IPWRA, below. The LAC-IPWRA estimator handles the case in which no observations are censored and requires the weaker independent censoring assumptions, which allows for fixed censoring times.

Weighted-adjusted-censoring IPWRA When a censoring model is specified, stteffects ipwra uses the formulas for the WAC-IPWRA estimator given in Weighted-adjusted-censoring IPWRA. The WAC-IPWRA estimator requires that some observations be censored and that the WAC assumptions hold.

LAC-IPWRA v.s WAC-IPWRA Estimate the parameters of a treatment-assignment model and compute inverse-probability-of treatment weights. Obtain the treatment-specific predicted mean outcomes for each subject by using the weighted maximum likelihood estimators. Compute the means of the treatment-specific predicted mean outcomes. Estimate the parameters of a treatment-assignment model and compute inverse-probability-of treatment weights. Estimate the parameters of a time-to-censoring model and compute inverse-probability-of censoring weights. Obtain the treatment-specific predicted mean outcomes for each subject by using the weighted maximum likelihood estimators. Compute the means of the treatment-specific predicted mean outcomes.

Example 1: Estimating the ATE by LAC-IPWRA → stteffects ipwra (age exercise diet education [weibull]) (smoke age exercise diet education [logit])

Example 2: Different outcome and treatment models

Example 3: Estimating the ATE by WAC-IPWRA

Example 4: Estimating the ATET by LAC-IPWRA

Postestimation tools for stteffects

Nonsmoker Smoker

Reference Cattaneo, M. D., D. M. Drukker, and A. D. Holland. 2013. Estimation of multivalued treatment effects under conditional independence. Stata Journal 13: 407–450.

Thank for your attention.