Table 4.

Synopsis of Minimally Important Difference and Responsiveness Metrics Across Six Trials

Variable	PEG	BPI Total	BPI Interference	BPI Severity	PEG-BPI Difference*
Cronbach’s alpha
Median	.73	.89	.88	.84	−.11 to −.16
Weighted Mean	.75	.89	.88	.83	−.08 to −.14
Minimally Important difference (MID)
Global anchor – A Little Better
Median	1.25	1.26	1.41	0.87	−.16 to +.38
Weighted Mean	1.28	1.06	1.28	0.81	.00 to +.47
0.35 standard deviation (SD)
Median	0.74	0.67	0.81	0.62	−.07 to +.12
Weighted Mean	0.77	0.71	0.84	0.65	−.07 to +.12
0.50 standard deviation (SD)
Median	1.05	0.95	1.15	0.88	−.10 to +.17
Weighted Mean	1.09	1.03	1.16	0.92	−.07 to +.17
1 SEM
Median	1.08	0.66	0.77	0.73	+.31 to +.42
Weighted Mean	1.06	0.64	0.80	0.75	+.26 to +.42
2 SEM
Median	2.16	1.33	1.53	1.46	+.63 to +.83
Weighted Mean	2.12	1.29	1.59	1.50	+.53 to +.83
Responsiveness
SRM for improvement, retrospective
Median	0.93	0.98	0.89	0.86	−.05 to +.07
Weighted Mean	0.89	0.90	0.81	0.84	−.01 to +.08
SRM for improvement, prospective
Median	0.85	0.76	0.75	0.72	+.09 to +.13
Weighted Mean	1.01	0.92	0.86	0.90	+.09 to +.15
AUC for any improvement
Median	0.73	0.77	0.73	0.75	−.04 to +.00
Weighted Mean	0.71	0.74	0.70	0.74	−.03 to +.01
AUC for moderate improvement
Median	0.74	0.77	0.71	0.76	−.03 to +.04
Weighted Mean	0.72	0.75	0.70	0.76	−.04 to +.02
Between-group Treatment Effect Size
Median	0.52	0.58	0.46	0.56	−.06 to +.06
Weighted Mean	0.51	0.57	0.50	0.52	−.06 to +.01

^*Range of differences between the PEG and the 3 BPI MID/responsiveness metrics calculated as PEG metric minus BPI metric. For example, the PEG-BPI difference in the 6 trials for the 0.50 standard deviation weighted mean is 1.09 – 1.03 = +.06 for the PEG-BPI Total difference; 1.09 – 1.16 = −.07 for the PEG-BPI Interference difference; and 1.09 – 0.92 = +.17 for the PEG-BPI Severity difference. Thus, the range is −.07 to +.17