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. Author manuscript; available in PMC: 2015 Nov 6.
Published in final edited form as: J Nerv Ment Dis. 2014 Jan;202(1):18–24. doi: 10.1097/NMD.0000000000000065

FIGURE 1.

FIGURE 1

Interpretation of clinically and statistically meaningful differences between treatments. The two-way arrows represent two-sided 95% CIs of differences between treatment groups defined as control minus experimental. The smallest MCID reduced by 25% to represent the NIM was used to evaluate the clinical relevance of treatment differences in contrast to the statistical significance test, which determines whether zero lies outside the 95% CI (CIs 1–6). If the 95% CI falls between the −NIM and the + NIM, one can be statistically confident that the treatments are mutually noninferior to each other (CIs 5, 6, and 7). Furthermore, when a lower measure of the effect is considered a better outcome, as with most symptom measures, when the upper confidence bound of the difference between treatments is lower than the +NIM, we can still conclude that the control is noninferior to the experimental treatment (CIs 1, 3, and 5–8) but not vice versa. Clinically meaningful superiority requires that the 95% CI lies entirely outside the interval of the range −MCID to + MCID (CIs 3 and 4). CIs 1, 2, 5, and 6 thus represent statistically significant superiority but not clinically meaningful superiority.