Forest plot generator
A forest plot displays individual study results (squares) along with their confidence intervals (horizontal lines). The size of the square represents the weight of the study. The pooled risk ratio is represented by a diamond, with the diamond's width indicating the 95% confidence interval for the pooled risk ratio. If the diamond does not overlap the vertical line at risk ratio = 1, it indicates that the overall effect is statistically significant.
Forest Plot Generator
Enter study data in the table below to generate a forest plot and its detailed analysis.
| Study | Risk Ratio | Lower CI | Upper CI | Weight |
|---|---|---|---|---|
| Study 1 | 1.5 | 1.1 | 2.0 | 50 |
Instructions
Input study data in the table provided. The table columns are:
- Study: The name or identifier for the study.
- Risk Ratio: The risk ratio (relative risk) calculated for the study.
- Lower CI: The lower bound of the 95% confidence interval for the risk ratio.
- Upper CI: The upper bound of the 95% confidence interval for the risk ratio.
- Weight: The weight assigned to the study based on its sample size or other relevant factors.
- Click "Add Row" to add more rows for additional studies.
- Click "Generate Forest Plot" to create a forest plot based on the input data.
- Click "Download Forest Plot" to download the generated forest plot as a PNG image.
Interpretation of Results
- Pooled Risk Ratio: The weighted average of the risk ratios from all studies.
- 95% CI: The 95% confidence interval for the pooled risk ratio.
- Heterogeneity: A measure of the variability between studies. (Note: This is a placeholder calculation for demonstration purposes. In practice, you would need to implement a more appropriate method for calculating heterogeneity, such as I² or Cochran's Q statistic.)
Example
Consider the following hypothetical data from three studies:
| Study | Risk Ratio | Lower CI | Upper CI | Weight |
|---|---|---|---|---|
| Study 1 | 1.5 | 1.1 | 2.0 | 50 |
| Study 2 | 2.0 | 1.5 | 2.6 | 30 |
| Study 3 | 1.8 | 1.3 | 2.4 | 20 |
Input this data into the table and click "Generate Forest Plot". The forest plot will show individual study results, and the narrative results section will display the pooled risk ratio, 95% CI, and heterogeneity. In this example, the pooled risk ratio might be around 1.71 with a 95% CI of [1.35, 2.08], indicating a statistically significant overall effect. Note that these values are hypothetical and may not match the actual output of the tool.