. 2019 Mar 27;25(8):1277–1290. doi: 10.1093/ibd/izz038

TABLE 5.

Descriptive Statistics and Measurement Properties of the IBDSI-SF

IBDSI-SF Scale	# Items	α	Total IBD Sample 1	CD Sample 1	UC Sample 1	F, CD vs UC	r with I	r with II	r with III	Test-retest reliability (over 2 weeks)	Test-retest reliability (over 2 months)
			Mean (SD), Min-Max	Mean (SD), Min-Max	Mean (SD), Min-Max		Sample 2	Sample 2	Sample 2	Sample 2	Sample 2
			N = 264	n = 140	n = 124		N = 154	N = 154	N = 154	N = 152	N = 147
Total Score	24	0.92	15.3 (13.3)	16.6 (12.5)	13.8 (14.0)	2.98	0.81	0.88	0.75	r = 0.83	r = 0.74
			0–67.0	0–60.0	0–67.0	P < 0.10	P < 0.001	P < 0.001	P < 0.001	P < 0.001	P < 0.001
I. Bowel Symptoms ^a	9	0.85	0.7 (0.7)	0.7 (0.7)	0.7 (0.8)	0.18	—			r = 0.88	r = 0.78
			0–3.6	0–2.8	0–3.6	P > 0.10				P < 0.001	P < 0.001
II. Abdominal & Bodily Discomfort^b	12	0.87	0.6 (0.6)	0.6 (0.6)	0.5 (0.5)	7.10	.46	—		r = 0.79	r = 0.71
			0–2.8	0–2.7	0–2.8	P < 0.01	P < 0.001			P < 0.001	P < 0.001
III. Fatigue	3	0.82	1.1 (0.9)	1.2 (0.9)	1.0 (0.9)	1.65	.44	.62	—	r = 0.71	r = 0.56
			0–3.7	0–3.3	0–3.7	P > 0.05	P < 0.001	P < 0.001		P < 0.001	P < 0.001

Note. The total score is calculated as a sum of the coded items. Subscale scores are calculated as the average of items on that scale. _aIncludes item 35 reporting on fistula activity, which in the long form is part of the Bowel Complications subscale. _bIncludes item 28 reporting on arthralgia/arthritis, which in the long form is part of the Systemic Complications subscale. r = Pearson correlations.