metaHelper (version 1.0.0)

SMD_from_mean_matched: Calculates SMD from Matched Groups

Description

Calculates the standardized mean differences for matched groups. Needs either the mean of the groups or the difference between groups. SD_within is usually not reported but can be calculated by the use of SD_within_from_SD_r().

Usage

SMD_from_mean_matched(M_diff = NA, M1 = NA, M2 = NA, SD_within)

Value

Standardized Mean Differences

Arguments

M_diff

mean difference between groups

M1

mean group 1 (in case M_diff not provided)

M2

mean group 2 (in case M_diff not provided)

SD_within

within standard deviation. CAVE this is usually not reported but needs to be computed from the difference standard deviation. This can be done with SD_within_from_SD_r().

References

M., Hedges, L.V., Higgins, J.P.T. and Rothstein, H.R. (2009). Converting Among Effect Sizes. In Introduction to Meta-Analysis (eds M. Borenstein, L.V. Hedges, J.P.T. Higgins and H.R. Rothstein). https://doi.org/10.1002/9780470743386.ch7

Examples

# Calcuation with group means
SMD_from_mean_matched(M1 = 103, M2 = 100, SD_within = 7.1005)

# Calculation with group difference
SMD_from_mean_matched(M_diff = 3, SD_within = 7.1005)

# Calculation with standard deviation between
# Correlation Coefficient between groups
r <- 0.7

# SD between groups
SD_between <- 5.5

SMD_from_mean_matched(M_diff = 3,
    SD_within = SD_within_from_SD_r(SD_between, r))