Related Experiment Video
Updated: Jun 16, 2026

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index
Published on: January 8, 2020
Are claims of advertisements in medical journals supported by RCTs?
L Heimans1, A van Hylckama Vlieg, F W Dekker
1Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Background:
Claims made in advertisements in medical journals might not always be supported by high-quality evidence, and referenced studies may have been sponsored by the pharmaceutical industry itself. We studied to what extent randomised controlled trials (RCTs) support the claims in advertisements in leading medical journals.
Methods:
Consecutive unique advertisements were selected from nine different medical journals, and evaluated by 250 medical students using a standardised score form. The quality of RCTs that were referenced in these advertisements was assessed with an instrument based on the Chalmers' score.
Results:
158 RCTs from 94 advertisements were used in the study. In total 55% of the RCTs had a high-quality score, 44% intermediate, and <1% had a low-quality score. Almost 40% of the RCTs had a high-quality score and at the same time supported the claim for which they were cited, while only 17% were also not sponsored by a pharmaceutical company.
Conclusion:
RCTs used to support claims in medical advertisements are often not a high-quality and independent source of evidence. This distracts from the credibility of claims in advertisements, even in the high-ranked journals.
Related Concept Videos
Clinical Trials
There are four phases in a clinical trial. A phase one...
Clinical Trials: Overview
Adrenergic Agonists: Therapeutic Uses
Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension.
Allergies and anaphylaxis:...
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, controlled...
Adrenergic Agonists: Therapeutic Classification
Vasopressor or pressor agents: They increase blood pressure and function as cardiac stimulants. Examples include endogenous catecholamines (norepinephrine and dopamine) and synthetic agents (phenylephrine).
Bronchodilators: β2-agonists can relax bronchial muscles and widen airways. They are commonly used for treating obstructive pulmonary...
Regression Toward the Mean
