Variables Definitions

1. Baseline SD: This represents the standard deviation of a set of data before any treatment or intervention. It is a measure of the amount of variation in the initial dataset.
2. Post-Treatment SD: This is the standard deviation of the same set of data after a treatment or intervention has been applied. It measures the amount of variation in the dataset following the treatment.
3. SD Change: The difference between the baseline standard deviation and the post-treatment standard deviation. It indicates how much the standard deviation has changed due to the treatment.
4. Correlation Coefficient (CC): The result of the conversion, representing the strength and direction of the linear relationship between the two variables. The correlation coefficient ranges from -1 to 1, where -1 indicates a perfect negative linear relationship, 1 indicates a perfect positive linear relationship, and 0 indicates no linear relationship.

Conversion Formula

The conversion from standard deviation to correlation coefficient is done using the following formula:

This formula is derived from the relationship between correlation coefficients and standard deviations.

**Formula Reference - Cochrane Handbook**