A dendrogram provides an indication of heterogeneity
change by inspecting the average within-cluster distance between
all possible combinations of clusters. A decision on the final number
of clusters is usually based on the combinations that do not yield a
substantial increase in heterogeneity [43]. From an inspection of the
dendrogram (Fig. 1), it was found that a division of either two or
three clusters could represent the appropriate solutions. However, the
three-cluster solution seemed to allowfor amore detailed classification
that would lead to a more meaningful comparison and interpretation
[47], hence the preferred solution.