Validity and Reliability of the Persian Version of Parkinson’s Disease Sleep Scale-2

Table 3

Interitem correlation for PDSS-2 in people with idiopathic Parkinson’s disease (n = 456).

Items	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
1	1
2	0.43	1
3	0.55	0.68	1
4	0.22	0.51	0.55	1
5	0.24	0.56	0.57	0.91	1
6	0.22	0.39	0.50	0.54	0.58	1
7	0.21	0.40	0.44	0.61	0.63	0.70	1
8	0.21	0.26	0.33	0.44	0.43	0.36	0.49	1
9	0.21	0.47	0.46	0.62	0.63	0.51	0.52	0.44	1
10	0.23	0.51	0.55	0.83	0.82	0.58	0.66	0.49	0.68	1
11	0.22	0.44	0.53	0.78	0.80	0.55	0.59	0.46	0.66	0.84	1
12	0.27	0.44	0.51	0.67	0.70	0.53	0.58	0.41	0.61	0.73	0.73	1
13	0.21	0.47	0.44	0.53	0.55	0.42	0.48	0.41	0.49	0.55	0.51	0.56	1
14	0.27	0.45	0.44	0.60	0.60	0.42	0.49	0.41	0.50	0.56	0.56	0.61	0.55	1
15	0.21	0.24	0.29	0.41	0.43	0.42	0.44	0.37	0.39	0.46	0.44	0.44	0.40	0.31	1

1, bad sleep quality; 2, difficulties falling asleep; 3, difficulties staying asleep; 4, restlessness of legs or arms at nights; 5, urge to move your legs or arms; 6, distressing dreams at night; 7, distressing hallucinations at night; 8, get up at night to pass urine; 9, uncomfortable and immobility at night; 10, pain in arms or legs; 11, muscle cramps in your arms or legs; 12, painful posturing in the morning; 13, tremor on waking; 14, tired and sleepy after waking in the morning; 15, snoring or difficulties in breathing.