Novel insights regarding the measurement properties of the SCOPA-AUT

BMC Neurology

Table 2 SCOPA-AUT item level Rasch model location and fit statistics (complete cases only, n = 404) ^a

Domains and items ^b	Location (SE) ^c	Fit Residual ^d	Chi-square	P-value
Gastrointestinal
1. Swallowing/choking	0.554 (0.085)	-0.500	1.153	0.949
2. Sialorrhea	-0.377 (0.065)	0.067	6.156	0.291
3. Dysphagia	0.702 (0.093)	-0.990	5.118	0.402
4. Early abdominal fullness	0.056 (0.072)	0.113	4.329	0.503
5. Constipation	0.152 (0.072)	-1.202	4.928	0.425
6. Straining for defecation	-0.476 (0.065)	-1.320	14.363	0.013 ^e
7. Faecal incontinence	0.841 (0.122)	0.587	4.08	0.538
Urinary
8. Urinary urgency	-0.378 (0.066)	-2.179	7.501	0.186
9. Urinary incontinence	-0.241 (0.067)	-2.519	10.466	0.063
10. Incomplete emptying	0.104 (0.075)	-0.958	4.95	0.422
11. Weak stream of urine	-0.219 (0.068)	-0.342	1.955	0.855
12. Frequency	-0.557 (0.069)	-0.710	5.325	0.377
13. Nocturia	-1.533 (0.058)	1.777	9.407	0.094
Cardiovascular
14. Lightheaded (standing up)	0.245 (0.079)	-0.563	2.177	0.824
15. Lightheaded (standing some time)	0.898 (0.091)	-0.650	3.238	0.663
16. Syncope	1.432 (0.201)	-0.991	5.756	0.331
Thermoregulatory
17. Hyperhidrosis during the day	0.159 (0.070)	-0.683	7.966	0.158
18. Hyperhidrosis during the night	0.150 (0.072)	0.094	2.691	0.747
20. Cold intolerance	-0.021(0.067)	0.825	8.94	0.111
21. Heat intolerance	0.202 (0.074)	0.389	7.386	0.193
Pupillomotor
19. Oversensitive to bright light	-0.051 (0.070)	0.194	13.875	0.016 ^e
Sexual
22. Sexual arousal problems ^f	-1.020 (0.068)	3.519	15.892	0.007 ^e
23. Orgasmic problems ^g	-0.622 (0.073)	-0.236	4.654	0.459

^a Excluding people (n = 2) with extreme scores (i.e., those scoring 0 and 69)
^b Items are presented by domain but were analyzed as a 23-item unidimensional scale
^c Item locations are expressed in logit values and represent the mean of each item’s response category threshold locations. Negative locations represent less autonomic dysfunction and positive locations represent more autonomic dysfunction
^d Standardized fit residuals represent discrepancies between observed and model-expected responses; should range between ± 2.5
^e Not significant following Bonferroni correction
^f Original items 22 (males; “erection problem”) and 24 (females; “vaginal problem”)
^g Original items 23 (males; “ejaculation problems”) and 25 (females; “problems with orgasm

ISSN: 1471-2377