Table 7.

Continuous moderators of light treatment effect on sleepiness and phase shift by using metaregression with mixed models.

Moderator	k	β	95% CI		p (Z)a	I2
			Lower	Upper
Outcome—sleepiness
Lux-hours (per 1000)	13	0.002	− 0.002	0.006	0.282	36.55
Light intensity (lux per 1000)	13	0.018	− 0.025	0.061	0.404	18.55
Treatment duration (daily hr)	14	− 0.019	− 0.069	0.031	0.453	18.81
Treatment duration (total hr)	14	− 0.007	− 0.017	0.004	0.192	29.12
Age (mean)	12	0.003	− 0.019	0.024	0.805	0
Female (%)	15	− 0.003	− 0.389	0.382	0.986	33.83
Sample size (n)	15	0.002	− 0.003	0.008	0.457	28.86
Outcome—phase shift
Lux-hours (per 1000)	11	0.014	0.004	0.024	0.008	35.51
Light intensity (lux per 1000)	11	0.286	0.061	0.512	0.013	39.68
Treatment duration (daily hr)	12	− 0.033	− 0.173	0.108	0.649	60.54*
Treatment duration (total hr)	12	− 0.010	− 0.047	0.027	0.596	62.44*
Age (mean)	11	− 0.052	− 0.092	− 0.013	0.009	29.04
Female (%)	12	0.154	− 1.162	1.470	0.819	50.48*
Sample size (n)	13	− 0.007	− 0.034	0.021	0.627	59.67*

*Significant at p < 0.05.

^aP value for the Z test of the moderator effect.