Effects of positive psychological control intervention on sleep and psychology of officers and soldiers working at sea

Table 2 Scores of Pittsburgh Sleep Quality Index dimensions of submarine officers and soldiers, n (%)

Index	Group	Before intervention				After intervention				χ2	P value
		0 point	1 point	2 points	3 points	0 point	1 point	2 points	3 points
Subjective sleep quality	Research group (n = 50)	6 (12.00)	23 (46.00)	17 (34.00)	4 (8.00)	13 (26.00)	28 (56.00)	8 (16.00)	1 (2.00)	8.109	0.044
	Control group (n = 71)	9 (12.68)	34 (47.89)	23 (32.39)	5 (7.04)	8 (11.27)	34 (47.89)	24 (33.80)	5 (7.04)	0.080	0.994
	χ2	0.092				9.066
	P value	0.993				0.028
Time to fall asleep	Research group (n = 50)	14 (28.00)	18 (36.00)	12 (24.00)	6 (12.00)	27 (54.00)	14 (28.00)	7 (14.00)	2 (4.00)	7.938	0.047
	Control group (n = 71)	20 (28.17)	25 (35.21)	17 (23.94)	9 (12.68)	20 (28.17)	23 (32.40)	18 (25.35)	10 (14.08)	0.165	0.983
	χ2	0.016				10.064
	P value	0.999				0.018
Actual sleep time	Research group (n = 50)	26 (52.00)	15 (30.00)	6 (12.00)	3 (6.00)	38 (76.00)	10 (20.00)	1 (2.00)	1 (2.00)	7.821	0.050
	Control group (n = 71)	37 (52.11)	21 (29.58)	9 (12.68)	4 (5.63)	35 (49.30)	21 (29.58)	10 (14.08)	5 (7.04)	0.219	0.974
	χ2	0.019				10.736
	P value	0.999				0.013
Sleep efficiency	Research group (n = 50)	1 (2.00)	48 (96.00)	1 (2.00)	0 (0.00)	10 (20.00)	39 (78.00)	1 (2.00)	0 (0.00)	8.295	0.016
	Control group (n = 71)	2 (2.82)	66 (92.96)	2 (2.82)	1 (1.40)	2 (2.82)	64 (90.14)	3 (4.23)	2 (2.81)	0.564	0.905
	χ2	0.891				11.091
	P value	0.828				0.011
Sleep disorder	Research group (n = 50)	12 (24.00)	28 (56.00)	9 (18.00)	1 (2.00)	25 (50.00)	20 (40.00)	4 (8.00)	1 (2.00)	7.824	0.050
	Control group (n = 71)	17 (23.94)	40 (56.34)	13 (18.31)	1 (1.41)	17 (23.94)	38 (53.52)	15 (21.13)	1 (1.41)	0.194	0.979
	χ2	0.064				10.139
	P value	0.996				0.017
Hypnotic drug	Research group (n = 50)	43 (86.00)	4 (8.00)	2 (4.00)	1 (2.00)	49 (98.00)	1 (2.00)	0 (0.00)	0 (0.00)	5.191	0.158
	Control group (n = 71)	66 (92.96)	3 (4.22)	2 (2.82)	0 (0.00)	64 (90.14)	3 (4.23)	3 (4.22)	1 (1.41)	1.231	0.746
	χ2	2.424				3.450
	P value	0.489				0.327
Daytime dysfunction	Research group (n = 50)	9 (18.00)	16 (32.00)	18 (36.00)	7 (14.00)	20 (40.00)	17 (34.00)	9 (18.00)	4 (8.00)	8.021	0.046
	Control group (n = 71)	13 (18.31)	22 (30.99)	25 (35.21)	11 (15.49)	12 (16.90)	23 (32.39)	26 (36.62)	10 (14.09)	0.129	0.988
	χ2	0.060				10.397
	P value	0.996				0.015

Subjective sleep quality: “very good” is 0 points, “good” is 1 point, “poor” is 2 points, “very poor” is 3 points. Time to sleep: “0” scores 0 points, “1-2” scores 1 point, “3-4” scores 2 points, “5-6” counts as 3 points. Sleep time: “> 7 hours” scores 0 points, “6 to 7” scores 1 point, “5 to 6” scores 2 points, “< 5 hours” counts as 3 points. Sleep efficiency: “> 85%” scored 0 points, “75%-84%” scored 1 point, “65%-74%” scored 2 points, “< 65%” scored 3 points. Sleep disorders: “0” scores 0 points, “1-9” scores 1 point, “10-18” scores 2 points, “19-27” counts as 3 points. Hypnotic drugs: “None” scores 0 points, “< 1 week/dose” scores 1 point, “1 to 2 weeks/dose” scores 2 points, “≥ 3 weeks/dose” is 3 points. Daytime dysfunction: “0” counts as 0 points, “1 to 2” counts as 1 point, “3 to 4” counts as 2 points, “5 to 6” counts as 3 points. The higher the score, the worse the status of each factor of sleep quality.