Efficacy and hypnotic effects of melatonin in shift-work nurses: double-blind, placebo-controlled crossover trial

Table 3 Subjective assessment of insomnia: results at baseline and after 1 night of melatonin or placebo treatment (N = 86)

		Mean	SD	P(vs.baseline^a)	P(vs.placebo^a)	F^b	P^b
Difficulty falling asleep	Melatonin	1.63	0.61	< 0.05	< 0.05	4.5	0.01
	Placebo	2.53	0.62	> 0.05
	Baseline	2.67	0.80
Difficulty staying asleep	Melatonin	2.32	0.83	> 0.05	> 0.05	0.71	NS
	Placebo	2.31	0.69	> 0.05
	Baseline	2.48	1.11
Problem waking up too early	Melatonin	2.26	0.81	> 0.05	> 0.05	0.42	NS
	Placebo	2.40	0.74	> 0.05
	Baseline	2.39	1.29
Sleep quality	Melatonin	2.58	0.76	< 0.05	< 0.05	1.2	0.02
	Placebo	2.69	0.67	> 0.05
	Baseline	3.16	0.92