Related Experiment Video
Updated: Mar 29, 2026

Inverse Probability of Treatment Weighting Propensity Score using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
An Evaluation of Weighting Methods Based on Propensity Scores to Reduce Selection Bias in Multilevel Observational
Walter L Leite1, Francisco Jimenez1, Yasemin Kaya1
1a College of Education , University of Florida.
Abstract:
Observational studies of multilevel data to estimate treatment effects must consider both the nonrandom treatment assignment mechanism and the clustered structure of the data. We present an approach for implementation of four propensity score (PS) methods with multilevel data involving creation of weights and three types of weight scaling (normalized, cluster-normalized and effective), followed by estimation of multilevel models with the multilevel pseudo-maximum likelihood estimation method. Using a Monte Carlo simulation study, we found that the multilevel model provided unbiased estimates of the Average Treatment Effect on the Treated (ATT) and its standard error across manipulated conditions and combinations of PS model, PS method, and type of weight scaling. Estimates of between-cluster variances of the ATT were biased, but improved as cluster sizes increased. We provide a step-by-step demonstration of how to combine PS methods and multilevel modeling to estimate treatment effects using multilevel data from the Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K).
Related Concept Videos
Strategies for Assessing and Addressing Confounding
Confounding can be addressed at both the design phase of a study and through analytical methods after data...
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...
Bias in Epidemiological Studies
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Study Designs in Epidemiology
Observational studies are those where the researcher does not intervene but rather observes natural variations. They include cross-sectional, cohort, and...
Study Design in Statistics
Does aspirin reduce the risk of heart attacks? Is one brand of fertilizer more effective at growing roses than another? Is fatigue as dangerous to a driver as the influence of alcohol? Questions like these are answered using randomized experiments with proper...
