Table 1.

Descriptive data of sociodemographic, sleep and fatigue variables by cluster.

	Milder sleep disturbance & milder fatigue (n = 61) n (%)	Milder sleep disturbance & severe fatigue (n = 68) n (%)	Severe sleep disturbance &milder fatigue (n = 15) n (%)	Severe sleep disturbance & severe fatigue (n = 15) n (%)

Gender					x² (3, N=159) = 0.69	p = .89
Female	35 (57.4%)	43 (63.2%)	9 (60.0%)	10 (61.0%)
Male	26 (42.6%)	25 (36.8%)	6 (40.0%)	5 (33.3%)
Occupation					x² (3, N=159) = 8.88	p = .03^*
Working	44 (74.6%) ^{a, b}	55 (82.1%) ^b	8 (53.3%) ^a	8 (53.3%) ^a
Not working / Retired	15 (25.4%) ^{a, b}	12 (17.9%) ^b	7 (46.7%) ^a	7 (46.7%) ^a
Marital Status					x² (9, N=159) = 3.55	p = .93
Single	6 (8.8%)	4 (6.6%)	2 (13.33%)	2 (13.33%)
Married / Common-law relationship	45 (66.2%)	43 (70.5%)	10 (66.7%)	11 (73.33%)
Divorced / Separated	12 (17.7%)	10 (16.4%)	3 (16.4%)	2 (13.33%)
Widowed	5 (7.4%)	4 (6.6%)	0 (0%)	0 (0%)
Type of insomnia					x² (9, N=159) = 4.56	p = .87
Initial	3 (4.5%)	1 (1.5%)	0 (0%)	0 (0%)
Middle	13 (21.3%)	18 (26.5%)	2 (13.3%)	3 (20.0%)
Late	1 (1.6%)	1 (1.5%)	0 (0%)	0 (0%)
Mixed	44 (72.1%)	48 (70.6%)	13 (86.7%)	12 (80.0%)
	M (SD)	M (SD)	M (SD)	M (SD)

Age (years)	52.4 (9.4)	47.5 (10.2)	53.3 (9.3)	51.7 (10.2)	F (3, 155) = 3.30	p = .02^*
Education (years)	14.6 (3.8) ^{a, b}	14.8 (3.2) ^{a, b}	16.4 (2.4) ^a	13.1 (4.9) ^b	F (3, 154) = 2.28,	p = .08
Insomnia duration (years)	15.62 (13.29)	16.40 (13.12)	18.20 (18.10)	16.52 (13.45)	F (3, 155) = 0.14	p = .93

PSG variables
SOL	14.78 (6.39) ^a	13.83 (7.50) ^a	26.39 (12.04)^b	33.28 (16.90) ^c	F (3, 155) = 26.47	p < .001^**
WASO	54.67 (22.41) ^a	50.07 (25.19) ^a	118.61 (36.14) ^c	96.19 (39.57) ^b	F (3, 155) = 35.93	p < .001^**
TST	367.54 (29.26) ^a	379.51 (33.57) ^a	285.04 (45.92) ^c	316.31 (31.51) ^b	F (3, 155) = 43.16	p < .001^**
% SE	83.70 (5.33) ^a	84.76 (5.40) ^a	65.25 (7.26) ^c	69.56 (6.14) ^b	F (3, 155) = 74.38	p < .001^**
NWAK	12.52 (4.02) ^a	10.88 (4.28) ^a	12.91 (3.84) ^a	17.01 (5.07) ^b	F (3, 155) = 8.96	p < .001^**
% Stage 1	5.34 (2.66) ^a	4.61 (2.63) ^a	8.27 (5.99) ^b	6.68 (3.61) ^a,b	F (3, 155) = 6.27	p < .001^**
% Stage 2	64.90 (5.65)	63.79 (7.45)	63.67 (6.14)	66.50 (4.76)	F (3, 155) = 0.91	p = .44
% Stages 3–4	5.92 (5.50)	8.01 (7.12)	8.68 (9.88)	6.91 (5.29)	F (3, 155) = 1.33	p = .27
% REM	12.52 (4.02) ^a	10.88 (4.28) ^a	12.91 (3.84) ^a	17.01 (5.07) ^b	F (3, 155) = 7.68	p < .001^**
Composite z-score	−0.21 (0.42) ^a	−0.37 (0.44) ^a	1.38 (0.62) ^b	1.14 (0.51) ^b	F (3, 155) = 94.71	p < .001^**

MFI subscales
General fatigue	9.75(2.41) ^a	14.40 (2.44) ^b	10.73 (3.19) ^a	15.47 (1.77) ^b	F (3, 155) = 48.97	p < .001^**
Physical fatigue	6.79(2.35) ^a	10.79 (2.61) ^b	7.00 (2.20) ^a	12.80 (3.23) ^c	F (3, 155) = 40.90	p < .001^**
Reduced activity	6.66 (1.78) ^a	10.38 (2.03) ^c	8.60 (2.53) ^b	13.80 (2.86) ^d	F (3, 155) = 62.48	p < .001^**
Reduced motivation	6.98 (2.14) ^a	10.59 (2.59) ^c	8.60 (2.53) ^b	9.93 (2.52) ^b,c	F (3, 155) = 24.90	p < .001^**
Mental fatigue	7.92 (2.64) ^a	12.56 (3.18) ^b	9.27 (2.68) ^a	12.93 (2.91) ^b	F (3, 155) = 31.73	p < .001^**
Composite z-score	−0.72 (−0.41) ^a	0.54 (0.40) ^b	−0.34 (.49) ^c	0.91 (0.41) ^d	F (3, 155) = 21.74	p < .001^**

p < .05

^**

p < .01

Note. Different letters indicate significant differences between clusters.