Table 2.

Exposure of control and case participants to the High Energy Visible (HEV) blue light generated by digital display screens.

Variable		Number of participants		P value
		Control	Breast cancer group
Digital Screen Use (hours/week)	<7	112	85	0.214
	7-14	42	42
	>14	23	29
Digital Screen Use in Dim Light (hours/day)	<0.25	33	22	0.885
	0.25–0.50	44	31
	>0.50	42	25
Size of Mobile Phone/Tablet Screen (inches)	<7	79	94	0.03
	7–15	126	90
	>15	86	91