Identifying Confounding by Indication through Blinded Prospective Review

Identifying confounding by indication through blinded prospective review.

Confounding by indication is a relentless threat to validity in observational studies of treatment effects. Multivariable models allow adjustment for known and readily measurable prognostic factors, but they may incompletely or inaccurately represent the underlying overall perceived risk of treatment. To incorporate practitioners' judgments about treatment indication and preprocedural prognosis...

Confounding by Indication: Response.

Assessment and control for confounding by indication in observational studies.

In the evaluation of pharmacologic therapies, the controlled clinical trial is the preferred design. When clinical trial results are not available, the alternative designs are observational epidemiologic studies. A traditional concern about the validity of findings from epidemiologic studies is the possibility of bias from uncontrolled confounding. In studies of pharmacologic therapies, confoun...

[Confounding bias due to indication and severity in observational studies].

Observational studies are subject to biases that may lead to misinterpretation of the results. This study aimed to determine the influence of omeprazole treatment on the duration of sick leave in patients with ankle sprains treated with non-steroidal anti-inflammatory drugs. We used the Ibermutuamur database. Contrary to our expectations, sick leave was longer in patients who received omeprazol...

When do confounding by indication and inadequate risk adjustment bias critical care studies? A simulation study

INTRODUCTION In critical care observational studies, when clinicians administer different treatments to sicker patients, any treatment comparisons will be confounded by differences in severity of illness between patients. We sought to investigate the extent that observational studies assessing treatments are at risk of incorrectly concluding such treatments are ineffective or even harmful due t...