Cited by 12,242Advanced Causal Inference TechniquesMeta-analysis and systematic reviewsStatistical Methods and Bayesian Inference

An Introduction to Propensity Score Methods for Reducing the Effects of Confounding in Observational Studies

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Austin, Peter C.·2011·Multivariate Behavioral Research

Abstract

The propensity score is the probability of treatment assignment conditional on observed baseline characteristics. The propensity score allows one to design and analyze an observational (nonrandomized) study so that it mimics some of the particular characteristics of a randomized controlled trial. In particular, the propensity score is a balancing score: conditional on the propensity score, the distribution of observed baseline covariates will be similar between treated and untreated subjects. I describe 4 different propensity score methods: matching on the propensity score, stratification on the propensity score, inverse probability of treatment weighting using the propensity score, and covariate adjustment using the propensity score. I describe balance diagnostics for examining whether the propensity score model has been adequately specified. Furthermore, I discuss differences between regression-based methods and propensity score-based methods for the analysis of observational data. I describe different causal average treatment effects and their relationship with propensity score analyses.

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Crossref · 10.1080/00273171.2011.568786

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  • The study used an active comparator, new-user design with propensity score matching that adjusted for baseline use of other antidiabetic drugs to minimize confounding by cotreatment.

    “The study maintained an active comparator, new-user design, with propensity score matching that adjusted for baseline use of other antidiabetic drugs to minimize confounding by cotreatment.39”

    From Neurodegeneration and Stroke After Semaglutide and Tirzepatide in Patients With Diabetes and Obesity (2025) · cites this paper as [39]

    The sections on propensity score matching and variable selection explain matching on propensity scores and including measured baseline covariates to address confounding (page numbers unavailable). They do not describe the citing study, an active-comparator new-user design, or adjustment for other antidiabetic drugs to minimize confounding by cotreatment. (LLM, conf=0.87)

    Experimental — accuracy not yet measured
  • The impact of implementation was evaluated using propensity score matching to account for potential confounding factors.

    “The impact of this implementation was evaluated by comparing clinical outcomes before and after system deployment, using propensity score matching to account for potential confounding factors43.”

    From Machine learning predicts sepsis deterioration trajectories. (2026) · cites this paper as [43]

  • Propensity score matching is considered a robust method.

    “PSM is considered a robust method (Austin, 2011; Benedetto et al., 2018).”
  • Propensity score matching is an analytic approach to reduce bias of measured confounding effects.

    “PSM is an analytic approach to reduce bias of measured confounding effects from covariates (Austin, 2011; Benedetto et al., 2018).”
  • Statistical models for confounding adjustment, including propensity scores and inverse probability weighting, rely on the assumption of no unmeasured confounding for the validity of the effect estimate.

    “All of these models, including more advanced techniques such as propensity scores [46] or inverse probability weighting, rely on the assumption of no unmeasured confounding for the validity of the effect estimate.”

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Research works printed but not linked: 1

  1. Rubin D.B. Matched sampling for causal effects 2006 New York, NY Cambridge University Press

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Authors
Austin, P. C.
Affiliations
University of Toronto (CA)
Corresponding author
Austin, Peter C.
Venue
Multivariate Behavioral Research
Published
2011-05-31
Volume
46
Issue
3
Pages
399-424
ISSN
  • 0027-3171 (ISSN-L)
  • 1532-7906
OpenAlex
W2036193982
Cited by
12,242
References
95
Citations by year
2026: 1460 · 2025: 1302 · 2024: 1187 · 2023: 1145 · 2022: 1277 · 2021: 1253 · 2020: 1065 · 2019: 850 · 2018: 781 · 2017: 628 · 2016: 560 · 2015: 353 · 2014: 221 · 2013: 122 · 2012: 28
FWCI
104.26
Type
journal article
Language
en
Open access
Locations
  • Multivariate Behavioral Research (publishedVersion)
  • Europe PMC (PubMed Central) (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Institute for Clinical Evaluative Sciences
  • Ontario Ministry of Health and Long-Term Care
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods and Bayesian Inference
Keywords
propensity score, confounding, observational studies, propensity score matching, stratification, inverse probability of treatment weighting, covariate adjustment, regression-based methods

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