Psychometric properties of a single-item scale to assess sleep quality among individuals with fibromyalgia

Table 1 Baseline patient characteristics and sleep scores

Characteristics	Study 1056 (N = 748)		Study 1077 (N = 745)
	n	%	n	%
Gender
Male	42	5.6	41	5.5
Female	706	94.4	704	94.5
Race
White	675	90.2	678	91.0
Black	35	4.7	33	4.4
Other	38	5.1	34	4.6
	N	Mean ± SD	N	Mean ± SD
Age (years)	748	48.8 ± 10.9	745	50.1 ± 11.4
Duration of FM Prior to Study Start (months)	747	111.7 ± 95.0	745	120.2 ± 96.2
Number of Painful Tender Points ^a	719	17.1 ± 1.6	723	16.9 ± 1.8
Baseline Mean Pain Score ^b	748	7.1 ± 1.3	745	6.7 ± 1.3
Sleep Quality Scale ^b	748	6.7 (1.7)	745	6.2 (1.6)
MOS Sleep Scales
Sleep Disturbance	744	67.8 ± 23.4	740	60.0 ± 24.9
Snoring	726	40.6 ± 35.9	717	36.7 ± 34.6
Awaken Short of Breath or with Headache	744	37.6 ± 31.1	743	32.3 ± 32.0
Quantity of Sleep	747	5.4 ± 1.6	744	5.6 ± 1.6
Sleep Adequacy	745	20.6 ± 22.0	744	23.7 ± 23.2
Somnolence	743	50.3 ± 24.1	740	42.1 ± 23.1
Sleep Problems Index (9-item)	741	65.0 ± 16.3	736	58.3 ± 17.7

SD = Standard Deviation
^a Total number of tender points with value >0 at randomization; the number is missing if any of 18 tender points is missing.
^b Baseline = Last 7 available pain scores before taking study medication up to and including Day1. If fewer than 7 scores are available then baseline consists of all scores that are available.

ISSN: 1477-7525