meta.lc.mean2: Confidence interval for a linear contrast of mean differences...

In dgbonett/vcmeta: Varying Coefficient Meta-Analysis

Confidence interval for a linear contrast of mean differences from 2-group studies

Description

Computes the estimate, standard error, and confidence interval for a linear contrast of 2-group mean differences from two or more studies. A Satterthwaite adjustment to the degrees of freedom is used to improve the accuracy of the confidence interval. Equality of variances within or across studies is not assumed.

Usage

meta.lc.mean2(alpha, m1, m2, sd1, sd2, n1, n2, v)

Arguments

alpha	alpha level for 1-alpha confidence
m1	vector of estimated means for group 1
m2	vector of estimated means for group 2
sd1	vector of estimated SDs for group 1
sd2	vector of estimated SDs for group 2
n1	vector of group 1 sample sizes
n2	vector of group 2 sample sizes
v	vector of contrast coefficients

Value

Returns 1-row matrix with the following columns:

• Estimate - estimated linear contrast

• SE - standard error

• LL - lower limit of the confidence interval

• UL - upper limit of the confidence interval

• df - degrees of freedom

References

\insertRef

Bonett2009avcmeta

Examples

m1 <- c(45.1, 39.2, 36.3, 34.5)
m2 <- c(30.0, 35.1, 35.3, 36.2)
sd1 <- c(10.7, 10.5, 9.4, 11.5)
sd2 <- c(12.3, 12.0, 10.4, 9.6)
n1 <- c(40, 20, 50, 25)
n2 <- c(40, 20, 48, 26)
v <- c(.5, .5, -.5, -.5)
meta.lc.mean2(.05, m1, m2, sd1, sd2, n1, n2, v)

# Should return:
#          Estimate       SE       LL       UL       df
# Contrast     9.95 2.837787 4.343938 15.55606 153.8362

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