Related Experiment Video
Updated: Sep 13, 2025

Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Inverse probability weighting for causal inference in hierarchical data
Lin Hu1, Jie Yu1, Chunxia Yang1
1Department of Epidemiology and Health Statistics, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, 610041, China.
Objective:
The aim of this study was to explore the impact of model misspecification, balance, and extreme weights on average treatment effect (ATE) estimation in hierarchical data with unmeasured cluster-level confounders using the multilevel propensity score model and inverse probability weight (IPW).
Methods:
We simulated 48 hierarchical data scenarios with unmeasured cluster-level confounders, fitting nine ATE estimation strategies. These strategies were combined with IPW, which used both marginal stabilized weights and cluster-mean stabilized weights. Extreme weights were handled by truncation. Moreover, these models were applied to data from patients co-infected with Human Immunodeficiency Virus (HIV) and Tuberculosis (TB) in Liangshan Prefecture, Sichuan, China, to estimate the ATE of TB treatment delay on treatment outcomes.
Results:
The simulation study revealed that FEM-Marginal tended to generate the most extreme weights, whereas BART-FE-Marginal considerably reduced the extreme weights in a large number of small clusters. When the data satisfied the positivity assumption, the marginal stabilized weight strategy had the largest absolute percentage bias and RMSE, whereas the cluster-mean stabilized weight strategy had the smallest. Case studies applying different ATE strategies have shown that among HIV-TB co-infected patients, TB treatment delay was a risk factor for treatment outcome.
Conclusions:
To better control unmeasured cluster-level confounders, it was more important to consider cluster characteristics when estimating ATE. The use of Bayesian additive regression trees (BART) for constructing multilevel propensity score models, or of cluster-mean stabilized weights is recommended. However, if marginal stabilized weights are used, extreme weight handling methods are necessary to improve effect estimation. In hierarchical data with unmeasured cluster-level confounders, reducing extreme weights, weight variability, and model misspecification while enhancing balance effectively minimizes estimation bias. The case study revealed that TB treatment delay remained associated with treatment outcomes even after accounting for unmeasured cluster-level confounders.
Related Concept Videos
Causality in Epidemiology
Weighted Mean
For example, consider the number of goals scored in the matches of a tournament. While computing the average number of goals scored in the tournament, it may be more important to...
Statistical Inference Techniques in Hypothesis Testing: Parametric Versus Nonparametric Data
Parametric statistics, as the name suggests, assumes that data follow a specific distribution, often a normal distribution. This assumption enables robust hypothesis testing and estimation. Parametric methods, like the Student's t-test or Goodness-of-fit test, are frequently employed in biostatistics due to their robustness. For instance,...
Parametric Survival Analysis: Weibull and Exponential Methods
Weibull Distribution
The Weibull distribution is a flexible model used in parametric survival analysis. It can handle both increasing and decreasing hazard rates, depending on its shape parameter...
Testing a Claim about Population Proportion
There are two methods of testing a claim about a population proportion: (1) Using the sample proportion from the data where a binomial distribution is approximated to the normal distribution and (2) Using the binomial probabilities calculated from the data.
The first method uses normal distribution as an approximation to the binomial distribution. The requirements are as follows: sample size is large...
Strategies for Assessing and Addressing Confounding
Confounding can be addressed at both the design phase of a study and through analytical methods after data...

