Computes the estimate, standard error, and confidence interval for a linear contrast of means from two or more studies. This function will use either an unequal variance (recommended) or an equal variance method. A Satterthwaite adjustment to the degrees of freedom is used with the unequal variance method.
meta.lc.mean1(alpha, m, sd, n, v, eqvar = FALSE)
alpha level for 1-alpha confidence
vector of estimated means
vector of estimated standard deviations
vector of sample sizes
vector of contrast coefficients
FALSE for unequal variance method
TRUE for equal variance method
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
Snedecor GW, Cochran WG (1980). Statistical methods, 7th edition. ISU University Pres, Ames, Iowa.
m <- c(33.5, 37.9, 38.0, 44.1)
sd <- c(3.84, 3.84, 3.65, 4.98)
n <- c(10, 10, 10, 10)
v <- c(.5, .5, -.5, -.5)
meta.lc.mean1(.05, m, sd, n, v, eqvar = FALSE)
#> Estimate SE LL UL df
#> Contrast -5.35 1.300136 -7.993583 -2.706417 33.52169
# Should return:
# Estimate SE LL UL df
# Contrast -5.35 1.300136 -7.993583 -2.706417 33.52169