replicate.stdmean2: Compares and combines 2-group standardized mean differences...

In dgbonett/vcmeta: Varying Coefficient Meta-Analysis

Compares and combines 2-group standardized mean differences in original and follow-up studies

Description

This function computes confidence intervals from an original study and a follow-up study where the effect size is a 2-group standardized mean difference. Confidence intervals for the difference and average effect size are also computed. Equality of variances within or across studies is not assumed. The confidence level for the difference is 1 – 2*alpha, which is recommended for equivalence testing. Square root unweighted variances, square root weighted variances, and single-group standard deviation are options for the standardizer.

Usage

replicate.stdmean2(
  alpha,
  m11,
  m12,
  sd11,
  sd12,
  n11,
  n12,
  m21,
  m22,
  sd21,
  sd22,
  n21,
  n22,
  stdzr
)

Arguments

alpha	alpha level for 1-alpha confidence
m11	estimated mean for group 1 in original study
m12	estimated mean for group 2 in original study
sd11	estimated SD for group 1 in original study
sd12	estimated SD for group 2 in original study
n11	sample size for group 1 in original study
n12	sample size for group 2 in original study
m21	estimated mean for group 1 in follow-up study
m22	estimated mean for group 2 in follow-up study
sd21	estimated SD for group 1 in follow-up study
sd22	estimated SD for group 2 in follow-up study
n21	sample size for group 1 in follow-up study
n22	sample size for group 2 in follow-up study
stdzr	set to 0 for square root unweighted average variance standardizer set to 1 for group 1 SD standardizer set to 2 for group 2 SD standardizer set to 3 for square root weighted average variance standardizer

Value

A 4-row matrix. The rows are:

• Row 1 summarizes the original study

• Row 2 summarizes the follow-up study

• Row 3 estimates the difference in standardized mean differences

• Row 4 estimates the average standardized mean difference

The columns are:

• Estimate - standardized mean difference estimate (single study, difference, average)

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

References

\insertRef

Bonett2021vcmeta

Examples

replicate.stdmean2(.05, 21.9, 16.1, 3.82, 3.21, 40, 40, 
                        25.2, 19.1, 3.98, 3.79, 75, 75, 0)

# Should return: 
#                           Estimate        SE         LL        UL
#  Original:              1.62803662 0.2594668  1.1353486 2.1524396
#  Follow-up:             1.56170447 0.1870576  1.2030461 1.9362986
#  Original - Follow-up:  0.07422178 0.3198649 -0.4519092 0.6003527
#  Average:               1.59487055 0.1599325  1.2814087 1.9083324

dgbonett/vcmeta documentation built on July 12, 2024, 3:12 p.m.