How To Calculate Weight In Meta Analysis

Meta-analysis is a statistical method used to combine the results of multiple scientific studies. Calculating the weight of each study in a meta-analysis is crucial as it determines the influence of each study on the overall result.

1. Enter the number of studies.
2. Enter the effect sizes of each study, separated by commas.
3. Enter the variances of each study, separated by commas.
4. Click ‘Calculate’.

The weight of each study is calculated using the following formula:

w_i = 1 / (v_i + (1/n) * (Q_chi^2 - k + 1))

Where:

• w_i is the weight of the i-th study.
• v_i is the variance of the i-th study.
• n is the number of studies.
• Q_chi^2 is the chi-square statistic.
• k is the number of groups.

Example Data for Meta-Analysis

Study	Effect Size	Variance

Calculated Weights for Example Data

Study	Weight

• Always ensure the data is reliable and relevant.
• Consider using a random-effects model for more heterogeneous studies.
• Interpret the results with caution, as meta-analysis has its limitations.

What is the difference between fixed-effects and random-effects models?

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For more information, see the CDC’s guide to understanding statistics.