Bias and sample size in intensive care unit trials: Protocol for a meta-epidemiological study

Area of Science:

• Critical care medicine
• Clinical trial methodology
• Meta-epidemiology

Background:

• Systematic and random errors impact the precision of intervention effect estimates in randomized clinical trials (RCTs) and meta-analyses.
• Assessing time trends in bias and sample size is crucial for understanding the reliability of intensive care unit (ICU) intervention studies.

Purpose of the Study:

• To evaluate temporal trends in the Cochrane risk of bias domains and sample size within RCTs of ICU interventions.
• To inform researchers, healthcare professionals, and policymakers about the evolving quality of ICU clinical trial evidence.

Main Methods:

• A meta-epidemiologic study of RCTs included in Cochrane systematic reviews of adult ICU interventions.
• Data extraction on risk of bias judgments across seven domains and trial sample sizes from reviews published since March 2011.
• Analysis of time trends using run charts, focusing on the proportion of trials with overall low risk of bias and median sample size.

Main Results:

• Time trends in the annual proportion of trials with overall low risk of bias will be assessed.
• Secondary outcomes include trends in annual median trial sample size and the proportion of trials with low, unclear, or high risk of bias in each domain.

Conclusions:

• The study will provide insights into the general reliability of findings from ICU RCTs over time.
• Results will inform future RCT design and reporting standards to enhance the quality and trustworthiness of critical care research.