Editorial: Use of Propensity Scores To Design Observational Comparative Effectiveness Studies

Matching with Propensity Scores to Reduce Bias in Observational Studies

In observational studies subjects are not randomly assigned to treatment and control groups. Therefore, both groups can be significantly different from each other and their differences after applying a treatment cannot be attributed to the treatment effect. Propensity scores methods offer a way to balance groups by matching treatment and control units based on a set of covariates. This paper ex...

Introduction to propensity scores: A case study on the comparative effectiveness of laparoscopic vs open appendectomy.

OBJECTIVE To demonstrate the use of propensity scores to evaluate the comparative effectiveness of laparoscopic and open appendectomy. DESIGN Retrospective cohort study. SETTING Academic and private hospitals. PATIENTS All patients undergoing open or laparoscopic appendectomy (n = 21 475) in the Public Use File of the American College of Surgeons National Surgical Quality Improvement Prog...

Propensity scores: a tool to help quantify treatment effects in observational studies

1. Methods in Epidemiologic, Clinical and Operations Research–MECOR–program, American Thoracic Society/Asociación Latinoamericana del Tórax, Montevideo, Uruguay. 2. Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA. 3. Divisão de Pneumologia, Instituto do Coração – InCor – Hospital das Clínicas, Faculdade de Medicina, Universidad...

GRACE principles: recognizing high-quality observational studies of comparative effectiveness.

Nonrandomized comparative effectiveness studies contribute to clinical and biologic understanding of treatments by themselves, via subsequent confirmation in a more targeted randomized clinical trial, or through advances in basic science. Although methodological challenges and a lack of accepted principles to assess the quality of nonrandomized studies of comparative effectiveness have limited ...

Using propensity score methods to analyse individual patient‐level cost‐effectiveness data from observational studies