Table 1.

Characteristics of the study population.

Variable	All n (%)	Dry eye group* n (%)	Previous dry eye diagnosis n (%)	Severe dry eye symptoms n (%)
Overall	3,107 (100)	398 (12.8)	317/3,107 (10.2)	151/3,107 (4.9)
Sex
Male	1067 (34.4)	105 (26.4)	71 (28.7)	34 (22.5)
Female	2032 (65.6)	293 (73.6)	176 (71.3)	117 (77.5)
Age category
18–39	1547 (50.3)	153 (38.9)	106 (43.5)	48 (32.2)
40–60	1052 (34.2)	139 (35.4)	86 (35.2)	52 (34.9)
60+	474 (15.3)	101 (25.7)	52 (21.3)	49 (32.9)
Dryness symptom
Never	1224 (39.4)	12 (3.0)	12 (4.9)	—
Sometimes	1170 (37.7)	65 (16.3)	65 (26.3)	—
Often	531 (17.1)	161 (40.5)	161 (65.2)	—
Constantly	182 (5.9)	160 (40.2)	9 (3.6)	151 (100)
Irritation symptom
Never	631 (20.3)	10 (2.5)	10 (4.0)	—
Sometimes	1475 (47.5)	99 (24.9)	98 (39.7)	—
Often	751 (24.2)	167 (42.0)	121 (49.0)	47 (31.1)
Constantly	250 (8.0)	122 (30.7)	18 (7.3)	104 (68.9)
Frequency of risk factors
+60 years	474 (15.4)	101 (25.6)	52 (21.3)	49 (32.5)
≥40 years	1526 (49.5)	240 (60.8)	183 (58.3)	102 (67.5)
Diabetes	247 (7.9)	41 (10.3)	23 (9.3)	18 (11.9)
Menopause	294 (14.5)	70 (23.9)	35 (19.9)	35 (29.9)
Rheumatologic diseases	143 (4.6)	32 (8.0)	18 (7.3)	13 (8.6)
Cancer treatment	35 (1.1)	11 (2.8)	7 (2.8)	4 (2.6)
Smoking	193 (7.8)	30 (9.3)	14 (6.9)	16 (13.4)
Computer use >6 h per day	789 (25.4)	124 (31.2)	82 (33.2)	43 (28.5)
Ocular surgery	328 (10.6)	79 (19.8)	38 (15.4)	41 (27.2)
Contact lens wear	310 (10.0)	60 (15.1)	45 (18.2)	15 (9.9)
Antidepressants	257 (8.8)	62 (15.6)	38 (15.4)	24 (15.9)
Anti-Allergy medications	348 (11.2)	83 (20.9)	47 (19.0)	36 (23.8)

⁺Dry eye was defined as clinical previous dry eye diagnosis or the presence of severe dry eye symptoms.