es_from_means_ci_pre_post {metaConvert}

Convert pre-post means of two independent groups into various effect size measures

Description

Convert pre-post means of two independent groups into various effect size measures

Usage

es_from_means_ci_pre_post(
  mean_pre_exp,
  mean_exp,
  mean_pre_ci_lo_exp,
  mean_pre_ci_up_exp,
  mean_ci_lo_exp,
  mean_ci_up_exp,
  mean_pre_nexp,
  mean_nexp,
  mean_pre_ci_lo_nexp,
  mean_pre_ci_up_nexp,
  mean_ci_lo_nexp,
  mean_ci_up_nexp,
  n_exp,
  n_nexp,
  r_pre_post_exp,
  r_pre_post_nexp,
  smd_to_cor = "viechtbauer",
  pre_post_to_smd = "bonett",
  reverse_means_pre_post
)

Arguments

mean_pre_exp

mean of the experimental/exposed group at baseline

mean_exp

mean of the experimental/exposed group at follow up

mean_pre_ci_lo_exp

lower bound of the 95% CI of the mean of the experimental/exposed group at baseline

mean_pre_ci_up_exp

upper bound of the 95% CI of the mean of the experimental/exposed group at baseline

mean_ci_lo_exp

lower bound of the 95% CI of the mean of the experimental/exposed group at follow up

mean_ci_up_exp

upper bound of the 95% CI of the mean of the experimental/exposed group at follow up

mean_pre_nexp

mean of the non-experimental/non-exposed group at baseline

mean_nexp

mean of the non-experimental/non-exposed group at follow up

mean_pre_ci_lo_nexp

lower bound of the 95% CI of the mean of the non-experimental/non-exposed group at baseline

mean_pre_ci_up_nexp

upper bound of the 95% CI of the mean of the non-experimental/non-exposed group at baseline

mean_ci_lo_nexp

lower bound of the 95% CI of the mean of the non-experimental/non-exposed group at follow up

mean_ci_up_nexp

upper bound of the 95% CI of the mean of the non-experimental/non-exposed group at follow up

n_exp

number of the experimental/exposed group

n_nexp

number of the non-experimental/non-exposed group

r_pre_post_exp

pre-post correlation in the experimental/exposed group

r_pre_post_nexp

pre-post correlation in the non-experimental/non-exposed group

smd_to_cor

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

pre_post_to_smd

formula used to convert the pre and post means/SD into a SMD (see details).

reverse_means_pre_post

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

Details

This function converts the bounds of the 95% CI of the pre/post means of two independent groups into standard errors (Section 6.3.1 in the Cochrane Handbook).

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

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

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_from_means_se_pre_post 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 15. Paired: pre-post means and dispersion'
	https://metaconvert.org/html/input.html

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.

Examples

es_from_means_ci_pre_post(
  n_exp = 36, n_nexp = 35,
  mean_pre_exp = 98,
  mean_pre_ci_lo_exp = 88,
  mean_pre_ci_up_exp = 108,
  mean_exp = 102,
  mean_ci_lo_exp = 92,
  mean_ci_up_exp = 112,
  mean_pre_nexp = 96,
  mean_pre_ci_lo_nexp = 86,
  mean_pre_ci_up_nexp = 106,
  mean_nexp = 102,
  mean_ci_lo_nexp = 92,
  mean_ci_up_nexp = 112,
  r_pre_post_exp = 0.8, r_pre_post_nexp = 0.8
)