Observational Studies
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Bias in Epidemiological Studies
Odds Ratio
Study Designs in Epidemiology
Confounding in Epidemiological Studies
You might also read
Articles linked to this work by shared authors, journal, and citation graph.
Updated: Oct 4, 2025

Symptom Assessment of Patients with Allergic Rhinitis Using an Allergen Exposure Chamber
Published on: March 3, 2023
Heng Li1, Chenguang Wang2, Wei-Chen Chen1
1Division of Biostatistics, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland, USA.
This study clarifies how weighting for covariate balance in observational studies relates to the estimand concept, specifically the population attribute, using the Rubin Causal Model. It examines three estimands to guide choices in clinical research.
Area of Science:
Background:
Purpose of the Study:
Main Methods:
Main Results:
Conclusions: