A Bayesian Nonparametric Approach for Estimating Individualized Treatment-Response Curves

TL;DR

This paper introduces a Bayesian nonparametric method for estimating individualized treatment response curves over time from observational data, enabling personalized decision-making in healthcare.

Contribution

It develops a novel BNP approach leveraging G-computation to model treatment response curves at both individual and population levels, improving accuracy over existing methods.

Findings

More accurate response estimates on hospital patient data

Flexible modeling of functional treatment response data

Enhanced posterior inference for personalized treatments

Abstract

We study the problem of estimating the continuous response over time to interventions using observational time series---a retrospective dataset where the policy by which the data are generated is unknown to the learner. We are motivated by applications where response varies by individuals and therefore, estimating responses at the individual-level is valuable for personalizing decision-making. We refer to this as the problem of estimating individualized treatment response (ITR) curves. In statistics, G-computation formula (Robins, 1986) has been commonly used for estimating treatment responses from observational data containing sequential treatment assignments. However, past studies have focused predominantly on obtaining point-in-time estimates at the population level. We leverage the G-computation formula and develop a novel Bayesian nonparametric (BNP) method that can flexibly model functional data and provide posterior inference over the treatment response curves at both the individual and population level. On a challenging dataset containing time series from patients admitted to a hospital, we estimate responses to treatments used in managing kidney function and show that the resulting fits are more accurate than alternative approaches. Accurate methods for obtaining ITRs from observational data can dramatically accelerate the pace at which personalized treatment plans become possible.