Table 5.

Risk factors for symptomatic dry eye compared with those without dry eye.

			Univariate ORa (95% CI)		P value		Multivariate-adjusted OR (95% CI)		P value
Age (years)
	15-20	1 [reference]		N/Ab		1 [reference]		N/A
	21-30	0.99 (0.85, 1.18)		.97		1.07 (0.88, 1.29)		.48
	31-40	0.68 (0.55, 0.82)		<.001		0.85 (0.67, 1.06)		.15
	41-50	0.69 (0.55, 0.88)		.002		0.99 (0.76, 1.28)		.94
	>50	0.47 (0.38, 0.58)		<.001		0.77 (0.60, 0.99)		.04
	Sex (female vs male)	2.06 (1.81, 2.34)		<.001		1.83 (1.59, 2.09)		<.001
VDTc use (hours/day)
	Less than 1 hour	1 [reference]		N/A		1 [reference]		N/A
	1-4 hours	1.11 (0.80, 1.53)		.53		1.08 (0.77, 1.50)		.67
	>4-6 hours	1.49 (1.10, 2.02)		.01		1.31 (0.96, 1.80)		.09
	>6-8 hours	1.87 (1.39, 2.55)		<.001		1.59 (1.15, 2.19)		.005
	>8 hours	2.29 (1.69, 3.12)		<.001		1.86 (1.35, 2.58)		<.001
Educational level
	Higher than bachelor’s degree	1 [reference]		N/A		1 [reference]		N/A
	Lower than bachelor’s degree	1.58 (1.31, 1.92)		<.001		1.30 (1.03, 1.64)		.02
	Bachelor’s degree	1..51 (1.30, 1.76)		<.001		1.18 (0.99, 1.39)		.06
Region
	Northeast	1 [reference]		N/A		1 [reference]		N/A
	Northern	0.90 (0.67, 1.23)		.51		0.93 (0.68, 1.27)		.64
	Central (except Bangkok)	0.72 (0.56, 0.92)		.008		0.76 (0.59, 0.98)		.03
	Bangkok	0.61 (0.49, 0.76)		<.001		0.64 (0.51, 0.81)		<.001
	Eastern	0.77 (0.56, 1.05)		.10		0.79 (0.57, 1.08)		.13
	Western	0.57 (0.37, 0.87)		.009		0.62 (0.40, 0.97)		.03
	Southern	0.66 (0.48, 0.90)		.01		0.68 (0.49, 0.93)		.02

^aOR: odds ratio

^bN/A: not applicable.

^cVDT: visual display terminal.