A nurse is reviewing literature for an evidence-based practice study. Which study should the nurse use for the $\mathbf{most}$ reliable level of evidence that uses statistics to show effectiveness?

A) Meta-analysis
B) Systematic review
C) Single random controlled trial
D) Control trial without randomization

Meta-Analysis

A statistical analysis that combines the results of multiple scientific studies to arrive at a comprehensive conclusion.

Systematic Review

A comprehensive summary of research literature, using explicit, rigorous methods to identify, assess, and synthesize studies on a specific topic.

Random Controlled Trial

A study design that randomly assigns participants into an experimental group or a control group to measure the efficacy of a treatment or intervention.