**Figure 3:** Diffogram (and associated 95% Tukey-Kramer-adjusted
confidence intervals) comparing pairs of adjusted (least-square)
mean CIMT values by route of exposure. Graph abbreviations:
‘Smoke’ for smoking, ‘Inject’ for injecting, ‘Snort’ for snorting, and
‘Multi’ for multiple routes. To determine the difference in adjusted
means for a pair of routes determine intersection of vertical line for
one route and horizontal line for the other route. The confidence
interval is interpreted as being perpendicular to the diagonal (45°)
dashed line. In particular, a confidence interval that crosses the
diagonal line indicates a pair of means is not significantly different
from each other (e.g. Snorting and Injecting) while a confidence
interval that does not cross the diagonal line indicates a pair of
means that are significantly different from one another (e.g.
Smoking and Injecting). |