Table 3

Occupational risk factors

VariablesCases
n (%)
Controls
n (%)
Total
n (%)
P value
Total
Night shift work history0.001
 Yes122 (24.65)172 (35.98)294 (30.22)
 No373 (75.35)306 (64.02)679 (69.78)
Types of shift work<0.001
 Permanent night shift4 (0.81)2 (0.42)6 (0.62)
 Rotating night shift79 (15.96)128 (26.78)207 (21.27)
 Irregular night shift39 (7.88)42 (8.79)81 (8.32)
 No373 (75.35)306 (64.02)679 (69.78)
Years of night shift work<0.001
 ≤18 (1.62)14 (2.93)22 (2.26)
 2–537 (7.47)52 (10.88)89 (9.15)
 6–1028 (5.66)52 (10.88)80 (8.22)
 ≥1149 (9.90)54 (10.48)103 (10.59)
 No373 (75.35)306 (64.02)679 (69.78)
Work posture<0.001
 Majority sitting, and sometimes standing or walking264 (53.33)313 (65.48)577 (59.30)
 Comparable sitting and standing118 (23.84)104 (21.76)222 (22.82)
 Majority standing or walking, and sometimes sitting113 (22.83)61 (12.76)174 (17.88)
Working hours per day0.191
 <224 (4.85)9 (1.88)33 (3.39)
 2–430 (6.06)20 (4.18)50 (5.14)
 5–7131 (26.46)157 (32.85)288 (29.6)
 ≥8310 (62.63)292 (61.09)602 (61.87)
Industrial dust0.001
 Yes450 (90.91)460 (96.23)910 (93.53)
 No45 (9.09)18 (3.77)63 (6.47)
High temperature at the office0.003
 Yes467 (94.34)469 (98.12)936 (96.20)
 No28 (5.66)9 (1.88)37 (3.80)