es_variab_from_means_ci function

Title

es_variab_from_means_ci(
  mean_exp,
  mean_nexp,
  mean_ci_lo_exp,
  mean_ci_up_exp,
  mean_ci_lo_nexp,
  mean_ci_up_nexp,
  n_exp,
  n_nexp,
  reverse_means_variability
)

Arguments

• mean_exp: mean of participants in the experimental/exposed group.
• mean_nexp: mean of participants in the non-experimental/non-exposed group.
• mean_ci_lo_exp: lower bound of the 95% CI of the mean of the experimental/exposed group
• mean_ci_up_exp: upper bound of the 95% CI of the mean of the experimental/exposed group
• mean_ci_lo_nexp: lower bound of the 95% CI of the mean of the non-experimental/non-exposed group.
• mean_ci_up_nexp: upper bound of the 95% CI of the mean of 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.
• reverse_means_variability: a logical value indicating whether the direction of the generated effect sizes should be flipped.

Returns

This function estimates VR and CVR

natural effect size measure	VR + CVR
converted effect size measure	No conversion performed
required input data	See 'Section 23. User's input (crude)'
	https://metaconvert.org/html/input.html

Details

This function converts the bounds of the 95% CI of the means of two independent groups into standard errors.

$$mean\_se\_exp = \frac{mean\_ci\_up\_exp - mean\_ci\_lo\_exp}{2 * qt{(0.975, df = n\_exp - 1)}}$$ $$mean\_se\_nexp = \frac{mean\_ci\_up\_nexp - mean\_ci\_lo\_nexp}{2 * qt{(0.975, df = n\_nexp - 1)}}$$

Then, calculations of the es_variab_from_means_se are applied.

Examples

es_variab_from_means_ci(
  mean_exp = 42, mean_ci_lo_exp = 32, mean_ci_up_exp = 52,
  mean_nexp = 42, mean_ci_lo_nexp = 37, mean_ci_up_nexp = 47,
  n_exp = 43, n_nexp = 34
)

References

Senior, A. M., Viechtbauer, W., & Nakagawa, S. (2020). Revisiting and expanding the meta-analysis of variation: The log coefficient of variation ratio. Research Synthesis Methods, 11(4), 553-567. https://doi.org/10.1002/jrsm.1423