Validation of the Italian translation of the perceived stigma scale and resilience assessment in inflammatory bowel disease patients

Table 1 Thresholds defining acceptable psychometric properties according to the International Quality of Life Assessment project

	Definition	Threshold
Data quality
Missing items	Unanswered items	< 5%-10%
	Incomplete scales (< 50% of items answered)	< 5%-10%
Floor and ceiling effect	Extreme scores (either on the lower- or higher-end)	< 10%
Scaling assumption
Internal consistency
Item	Correlation among items of the same scale (Pearson correlation ≥ 0.4)	> 90%
Reliability	Overall consistency of the scale (Cronbach’s alpha coefficient)	> 0.7
Discriminant validity	Items whose Pearson correlation with other scales is higher than with their scale	0%
Test-retest evaluation	Correlation between the results scales filled in twice by the same patients at defined time points (Pearson correlation)	> 0.7

Table 2 Demographic and clinical characteristics of the validating cohort

	Overall (n = 126)	CD (n = 57)	UC (n = 69)	P value
Age (mean ± SD)	46.13 (± 16.95)	42.29 (± 15.7)	49.29 (± 17.38)	0.03
Male	71 (56.4%)	33 (57.9%)	38 (55.1%)	0.86
BMI	23.9 (± 4.1)	23.9 (± 4.3)	23.9 (± 3.9)	0.67
Disease duration (median, IQR)	8 (3-16)	10 (3-17)	8 (3.5-13)	0.44
Disease characteristics (CD)
Location (CD)	-		-
Terminal ileum (L1)		13 (22.8%)
Colon (L2)		8 (14.0%)
Ileo-colon (L3)		28 (49.1%)
Upper GI (L4)		2 (3.5%)
Perianal disease (p)		19 (33.3%)
Behavior (CD)	-	-
Inflammatory (B1)		32 (56.1%)
Stricturing (B2)		25 (43.9%)
Penetrating (B3)		16 (28.1%)
Disease activity (HBI)	-	-
< 5		38 (66.7%)
5-7		14 (24.6%)
8-16		5 (8.8%)
> 16	-	0 (0%)
Disease characteristics (UC)			-
Location	-	-	7 (10.1%)
Proctitis (E1)			26 (37.7%)
Left sided (E2)			36 (52.2%)
Extensive (E3)
Disease activity (pMayo)	-
< 2			45 (65.2%)
2-4			13 (18.8%)
5-7			4 (5.8%)
> 7			7 (10.1%)
Pouch			3 (4.4%)
Extraintestinal manifestations	36 (28.6%)	17 (29.8%)	19 (27.5%)	0.84
Previous abdominal surgery	38 (30.2%)	22 (38.6%)	16 (42.1%)	0.07
Calprotectin				0.54
< 50	43(34.1%)	15 (26.3%)	28 (40.6%)
51-250	33 (16.2%)	17 (29.8%)	16 (23.2.%)
> 250	16 (12.7%)	7 (12.3%)	9 (13.4%)
Missing	34 (27.0%)	18 (31.6%)	16 (23.2%)
CRP				1.00
Normal	77 (61.1)	35 (62.4%)	42 (60.9%)
Raised	39 (31.0%)	18 (31.6%)	21 (30.4%)
Missing	10 (7.9%)	4 (7.0%)	6 (8.7%)
Comorbidities	40 (31.8%)	16 (28.1%)	24 (34.8%)	0.45
Cardiomyopathy	15 (11.9%)	3 (5.26%)	12 (17.4%)	0.05
Hypertension	28 (22.2%)	12 (42.9%)	16 (23.2%)	0.83
Diabetes	11 (8.73%)	4 (7.0%)	7 (10.1%)	0.75
Hepatic failure	1 (0.8%)	1 (1.8%)	0 (0.0%)	0.45
Kidney failure	4 (3.17%)	3 (5.26%)	1 (1.45%)	0.32
Respiratory failure	2 (1.6%)	1 (1.8%)	1 (1.5%)	1.00
Neurologic diseases	5 (4.0%)	1 (1.8%)	4 (5.8%)	0.37
Psychiatric disorder	15 (11.9%)	7 (12.3%)	8 (11.6%)	1.00
Onco-hematological diseases	12 (9.5%)	2 (3.5%)	10 (14.5%)	0.06

BMI: Body mass index; CD: Crohn’s disease; CRP: C-reactive protein; GI: Gastrointestinal; HBI: Harvey-Bradshaw Index; IQR: Interquartile range; PMS: Partial Mayo Score; SD: Standard deviation; UC: Ulcerative colitis.

Table 3 Psychometric characteristics of perceived stigma scale and its sub-scales

	Overall	Significant others	Healthcare professionals
Median score	0.45 (0.20-0.85)	0.70 (0.30-1.40)	0.10 (0-0.40)
Data quality
Missing items	0 (0%)	0 (0%)	0 (0%)
Floor effect	9 (7.1%)	11 (8.7%)	53 (42.1%)
Ceiling effect	0 (0%)	0 (0%)	0 (0%)
Scaling assumption
Internal consistency
Item	19/20 (95.0%)	10/10 (100%)	10/10 (100%)
Reliability (Cronbach alpha)	0.87	0.83	0.81
Discriminant validity	-	30.0%	30.0%
Test-retest	0.99 (0.99-1.00)	0.999 (0.99-1.00)	0.99 (0.97-0.99)
Evaluationa

^aIntraclass correlation coefficient (95% confidence interval).

Table 4 Correlation between inflammatory bowel disease perceived stigma scale scores and demographic or clinical characteristics

	PSS	P	Spearman’s correlation (95%CI)	PSS SO	P	Spearman’s correlation (95%CI)	PSS HP	P	Spearman’s correlation (95%CI)
Median score (IQR)	0.45 (0.20 to 0.85)			0.70 (0.30 to 1.40)			0.10 (0.00 to 0.40)
Age		0.11	-0.14 (-0.31 to 0.03)		0.08	-0.157 (-0.33 to 0.02)		0.20	-0.116 (-0.29 to 0.06)
Sex		0.51			0.26			0.29
Female	0.45 (0.30 to 0.85)			0.70 (0.50 to 1.40)			0.10 (0.00 to 0.40)
Male	0.45 (0.15 to 0.90)			0.70 (0.20 to 1.40)			0.10 (0.00 to 0.50)
Diagnosis		0.33			0.35			0.34
CD	0.55 (0.25 to 0.95)			0.80 (0.40 to 1.40)			0.10 (0.00 to 0.50)
UC	0.45 (0.20 to 0.85)			0.70 (0.30 to 1.30)			0.10 (0.00 to 0.40)
HBI		0.91	0.05 (-0.22 to 0.30)		0.91	0.05 (-0.21 to 0.31)		0.70	0.11 (-0.16 to 0.36)
< 5	0.53 (0.25 to 0.80)			0.75 (0.50 to 1.30)			0.10 (0.00 to 0.50)
5-7	0.60 (0.10 to 1.15)			0.90 (0.20 to 1.60)			0.30 (0.00 to 0.50)
8-16	0.40 (0.10 to 1.40)			0.70 (0.20 to 1.80)			0.10 (0.00 to 0.80)
pMS		0.52	0.06 (-0.18 to 0.29)		0.44	0.03 (-0.21 to 0.26)		0.81	0.11 (-0.13 to 0.34)
< 2	0.40 (0.20 to 0.85)			0.60 (0.40 to 1.30)			0.10 (0.00 to 0.30)
2-4	0.45 (0.05 to 0.75)			0.60 (0.10 to 1.20)			0.20 (0.00 to 0.40)
5-7	0.75 (0.48 to 1.22)			1.40 (0.90 to 1.75)			0.15 (0.05 to 0.70)
> 7	0.35 (0.15 to 1.50)			0.70 (0.00 to 2.70)			0.10 (0.00 to 0.70
CD-RISC25	-	0.03	-0.20 (-0.36 to -0.02)	-	0.02	-0.20 (-0.36 to -0.03)	-	0.12	-0.14 (-0.31 to 0.04)

CD: Crohn’s disease; CD-RISC25: 25-item Connor-Davidson Resilience Scale; CI: Confidence interval; HBI: Harvey-Bradshaw Index; HP: Healthcare professionals; IQR: Interquartile range; pMS: Partial Mayo Score; SO: Significant others; UC: Ulcerative colitis.