es_from_means_se function

Convert means and standard errors of two independent groups several effect size measures

es_from_means_se(
  mean_exp,
  mean_se_exp,
  mean_nexp,
  mean_se_nexp,
  n_exp,
  n_nexp,
  smd_to_cor = "viechtbauer",
  reverse_means
)

Arguments

• mean_exp: mean of participants in the experimental/exposed group.
• mean_se_exp: standard error of participants in the experimental/exposed group.
• mean_nexp: mean of participants in the non-experimental/non-exposed group.
• mean_se_nexp: standard error of participants in the non-experimental/non-exposed group.
• 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_means: a logical value indicating whether the direction of the generated effect sizes should be flipped.

Returns

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 9. Means and dispersion (crude)'
	https://metaconvert.org/input.html

Details

This function converts the standard errors of two independent groups into standard deviations, and then relies on the calculations of the es_from_means_sd() function.

To convert the standard errors into standard deviations , the following formula is used.

$$mean\_sd\_exp = mean\_se\_exp * \sqrt{n\_exp}$$ $$mean\_sd\_nexp = mean\_se\_nexp * \sqrt{n\_nexp}$$

Then, calculations of the es_from_means_sd() are applied.

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

Examples

es_from_means_se(
  mean_exp = 42, mean_se_exp = 11,
  mean_nexp = 42, mean_se_nexp = 15,
  n_exp = 43, n_nexp = 34
)

References

Higgins JPT, Li T, Deeks JJ (editors). Chapter 6: Choosing effect size measures and computing estimates of effect. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.3 (updated February 2022). Cochrane, 2022. Available from www.training.cochrane.org/handbook.