R/meta_rep.R
replicate.mean2.Rd
This function computes confidence intervals from an original study and a follow-up study where the effect size is a 2-group mean difference. Confidence intervals for the difference and average effect size are also computed. Equality of variances within or across studies is not assumed. A Satterthwaite adjustment to the degrees of freedom is used to improve the accuracy of the confidence intervals. The same results can be obtained using the meta.lc.mean2 function with appropriate contrast coefficients. The confidence level for the difference is 1 – 2*alpha, which is recommended for equivalence testing.
replicate.mean2(
alpha,
m11,
m12,
sd11,
sd12,
n11,
n12,
m21,
m22,
sd21,
sd22,
n21,
n22
)
alpha level for 1-alpha confidence
estimated mean for group 1 in original study
estimated mean for group 2 in original study
estimated SD for group 1 in original study
estimated SD for group 2 in original study
sample size for group 1 in original study
sample size for group 2 in original study
estimated mean for group 1 in follow-up study
estimated mean for group 2 in follow-up study
estimated SD for group 1 in follow-up study
estimated SD for group 2 in follow-up study
sample size for group 1 in follow-up study
sample size for group 2 in follow-up study
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 mean differences
Row 4 estimates the average mean difference
The columns are:
Estimate - mean difference estimate (single study, difference, average)
SE - standard error
t - t-value
p - p-value
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
df - degrees of freedom
Bonett DG (2021). “Design and analysis of replication studies.” Organizational Research Methods, 24(3), 513--529. ISSN 1094-4281, doi:10.1177/1094428120911088 .
replicate.mean2(.05, 21.9, 16.1, 3.82, 3.21, 40, 40,
25.2, 19.1, 3.98, 3.79, 75, 75)
#> Estimate SE t p LL
#> Original: 5.80 0.7889312 7.3517180 1.927969e-10 4.228624
#> Follow-up: 6.10 0.6346075 9.6122408 0.000000e+00 4.845913
#> Original - Follow-up: -0.30 1.0124916 -0.2962988 7.673654e-01 -1.974571
#> Average: 5.95 0.5062458 11.7531843 0.000000e+00 4.950627
#> UL df
#> Original: 7.371376 75.75255
#> Follow-up: 7.354087 147.64728
#> Original - Follow-up: 1.374571 169.16137
#> Average: 6.949373 169.16137
# Should return:
# Estimate SE t p
# Original: 5.80 0.7889312 7.3517180 1.927969e-10
# Follow-up: 6.10 0.6346075 9.6122408 0.000000e+00
# Original - Follow-up: -0.30 1.0124916 -0.2962988 7.673654e-01
# Average: 5.95 0.5062458 11.7531843 0.000000e+00
# LL UL df
# Original: 4.228624 7.371376 75.75255
# Follow-up: 4.845913 7.354087 147.64728
# Original - Follow-up: -1.974571 1.374571 169.16137
# Average: 4.950627 6.949373 169.16137