es_from_md_sd {metaConvert}

Convert a mean difference between two independent groups and standard deviation into several effect size measures

Description

Convert a mean difference between two independent groups and standard deviation into several effect size measures

Usage

es_from_md_sd(md, md_sd, n_exp, n_nexp, smd_to_cor = "viechtbauer", reverse_md)

Arguments

md

mean difference between two independent groups

md_sd

standard deviation of the mean difference

n_exp

number of participants in the experimental/exposed group.

n_nexp

number of participants in the non-experimental/non-exposed group.

smd_to_cor

formula used to convert the cohen_d value into a coefficient correlation (see details).

reverse_md

a logical value indicating whether the direction of generated effect sizes should be flipped.

Details

This function converts the mean difference and 95% CI into a Cohen's d (D) and Hedges' g (G). Odds ratio (OR) and correlation coefficients (R/Z) are then converted from the Cohen's d.

The formula used to obtain the Cohen's d is:

d = \frac{md}{md\_sd}

Note that this formula is perfectly accurate only if the md_sd has been estimated by assuming that the variance of the two groups is equal.

To estimate other effect size measures, calculations of the es_from_cohen_d() are applied.

Value

This function estimates and converts between several effect size measures.

natural effect size measure	MD + D + G
converted effect size measure	OR + R + Z
required input data	See 'Section 10. Mean difference and dispersion (crude)'
	https://metaconvert.org/html/input.html

Examples

es_from_md_sd(md = 4, md_sd = 2, n_exp = 20, n_nexp = 22)