(14%) were characterized as high challenge sites in relation to the
coordination with their CTU.
Next, we tallied the number of moderate and significant challenges
endorsed by the sites related to specific activities within
each domain. A Kruskal–Wallis test was conducted for each
domain to evaluate differences between groups of sites reported
level of challenge coordinating with their respective CTU (low
versus high) on the median number of items endorsed as either a
moderate or significant challenge. The test, which was corrected
for tied ranks, was significant for all eight domains (P < 0.05).
Thus, those characterized as high challenge sites in coordinating
with their CTU also endorsed significantly more moderatesignificant
challenges at their site within each domain (P < 0.05).
The largest differences between the groups were found in the Staff
Education and Training, Protocol Implementation, and Fiscal and
Resources domains. The proportion of variability in the ranked
dependent variable accounted for by level of challenge variable
was between η2 = 0.10 and η2 = 0.24, indicating a moderate to
strong relationship between level of challenge coordinating with
the CTU and the number of items endorsed as moderate or significant
across the eight domains. The results of these analyses are
listed in Table 4 later