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

Table 4 Trait Mental Toughness Scale-II scores of submarine officers and soldiers

Index	Group	Before intervention	After intervention	t	P value
Positive score	Research group (n = 50)	34.70 ± 0.46	36.94 ± 0.47	-28.514	< 0.001
	Control group (n = 71)	34.66 ± 0.51	34.65 ± 0.48	0.159	0.874
	t	0.422	26.056
	P value	0.674	< 0.001
Negative score	Research group (n = 50)	20.48 ± 0.50	17.82 ± 0.44	25.236	< 0.001
	Control group (n = 71)	20.38 ± 0.49	20.46 ± 0.50	-0.973	0.334
	t	1.090	-30.052
	P value	0.278	< 0.001