match.allocate: Allocation of matched units to intervention arms

In Syksy/hamlet: Hierarchical Optimal Matching and Machine Learning Toolbox

Allocation of matched units to intervention arms

Description

This function allocates units belonging to a single submatch to separate intervention arms. This ensures that the resulting intervention groups are homogeneous in respect to the variables that were used to construct the distance/dissimilarity matrix for the non-bipartite matching. The number of resulting intervention groups is equal to the 'g' (i.e. submatch size) used in the multigroup non-bipartite matching.

Usage

match.allocate(xmat)

Arguments

xmat	A binary matching matrix or a matching vector given by match.bb-function.

Value

A vector where each element indicates to which group the observation was randomized to. The group names are "Group_A", "Group_B", "Group_C", ... until 'g' letters, where 'g' was the size of submatches.

Author(s)

Teemu Daniel Laajala <[e-mail]>

See Also

match.bb match.mat2vec match.vec2mat match.dummy

Examples

data(vcapwide)

# Construct an Euclidean distance example distance matrix using 15 observations from the VCaP study
d <- as.matrix(dist(vcapwide[1:15,c("PSAWeek10", "BWWeek10")]))
# Matching using the b&b algorithm to submatches of size 3 
# (which will result in 3 intervention groups)
bb3 <- match.bb(d, g=3)
str(bb3)

solvec <- bb3$solution 
# matching vector, where each element indicates to which submatch each observation belongs to

# Perform an example random allocation of the above submatches, 
# these will be randomly allocated to 3 arms based on the submatches
set.seed(1)
groups <- match.allocate(solvec)

# Illustrate randomization, no baseline differences in these three artificial groups
by(vcapwide[1:15,c("PSAWeek10", "BWWeek10")], INDICES=groups, FUN=function(x) x)

summary(aov(PSAWeek10 ~ groups, data = data.frame(PSAWeek10 = vcapwide[1:15,"PSAWeek10"], groups)))
summary(aov(BWWeek10 ~ groups, data = data.frame(BWWeek10 = vcapwide[1:15,"BWWeek10"], groups)))

Syksy/hamlet documentation built on Aug. 28, 2023, 6:52 a.m.