Meta-Analysis Skill

Purpose

Quantitatively synthesize results across multiple studies.

Meta-Analysis Steps

1. Extract Effect Sizes

• Convert to common metric (d, OR, RR)
• Calculate standard errors

2. Choose Model

• Fixed-effect: Assumes single true effect
• Random-effects: Allows heterogeneity

3. Pool Results

• Weight studies (inverse variance)
• Calculate summary effect
• 95% confidence interval

4. Assess Heterogeneity

• I² statistic (0-100%)
  • 0-40%: Low heterogeneity
  • 40-75%: Moderate
  • 75-100%: High
• Q test (statistical significance)

5. Investigate Heterogeneity

• Subgroup analysis
• Meta-regression
• Sensitivity analysis

6. Publication Bias

• Funnel plot
• Egger's test
• Trim-and-fill

Reporting

Example: "Meta-analysis of 15 RCTs (N=1,234) showed a moderate effect, g=0.52, 95% CI[0.38, 0.66], p<.001. Heterogeneity was moderate, I²=58%, suggesting variability in effects."

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Version: 1.0.0