Table 2 Associations of measures of patterns of sunlight exposure in BCC and SCC cases and controls

Blistering Sunburn

No

101 (32.3)

54 (25.0)

1.00 (reference)

1.00 (reference)

38 (23.0)

1.00 (reference)

1.00 (reference)

Yes

212 (67.7)

162 (75.0)

1.96 (1.27-3.03)

1.56 (0.96-2.54)

127 (77.0)

2.02 (1.22-3.33)

1.24 (0.71-2.18)

Job in sun ≥3 months

No

227 (72.8)

120 (55.3)

1.00 (reference)

1.00 (reference)

86 (51.8)

1.00 (reference)

1.00 (reference)

Yes

85 (27.2)

97 (44.7)

1.38 (0.89-2.14)

1.31 (0.81-2.12)

80 (48.2)

1.73 (1.06-2.83)

1.72 (0.99-2.97)

# years with job

≤10

57 (18.7)

47 (22.3)

1.17 (0.70-1.94)

1.07 (0.61-1.86)

44 (27.0)

1.64 (0.94-2.86)

1.64 (0.88-3.07)

>10

21 (6.9)

44 (20.9)

2.14 (1.12-4.11)

2.12 (1.05-4.27)

33 (20.2)

2.54 (1.23-5.28)

2.36 (1.07-5.20)

p_trend = 0.03

p_trend = 0.06

p_trend = 0.01

p_trend = 0.02

Lifetime tanning bed use

209 (71.3)

175 (82.5)

1.00 (reference)

1.00 (reference)

127 (80.9)

1.00 (reference)

1.00 (reference)

Never used

44 (15.0)

25 (11.8)

0.99 (0.56-1.76)

0.99 (0.53-1.82)

18 (11.5)

1.01 (0.52-1.98)

0.80 (0.38-1.71)

1–10 times

40 (13.7)

12 (5.7)

0.64 (0.30-1.36)

0.64 (0.30-1.36)

12 (7.6)

1.67 (0.75-3.73)

1.85 (0.74-4.62)

>10 times

p_trend = 0.32

p_trend = 0.20

p_trend = 0.29

p_trend = 0.40

Apply SPF³ ≥15

Always/often

124 (39.6)

82 (37.8)

1.00 (reference)

1.00 (reference)

53 (32.5)

1.00 (reference)

1.00 (reference)

Sometimes

98 (31.3)

59 (27.2)

0.79 (0.50-1.26)

0.87 (0.52-1.45)

56 (34.4)

0.83 (0.49-1.42)

0.86 (0.47-1.59)

Rarely/never

91 (29.1)

76 (35.0)

0.83 (0.52-1.32)

0.93 (0.56-1.54)

54 (33.1)

0.79 (0.46-1.36)

0.87 (0.48-1.60)

Cumulative sunlight exposure

Low

87 (32.3)

52 (27.4)

1.00 (reference)

1.00 (reference)

35 (22.7)

1.00 (reference)

1.00 (reference)

Medium

92 (34.2)

54 (28.4)

1.02 (0.61-1.69)

1.42 (0.81-2.50)

57 (37.0)

1.49 (0.84-2.64)

2.36 (1.22-4.57)

High

90 (33.5)

84 (44.2)

1.37 (0.83-2.27)

1.88 (1.07-3.31)

62 (40.3)

1.59 (0.88-2.87)

2.47 (1.25-4.91)

Intermittent sunlight exposure

Low

91 (33.8)

80 (42.1)

1.00 (reference)

1.00 (reference)

59 (38.3)

1.00 (reference)

1.00 (reference)

Medium

84 (31.2)

52 (27.4)

0.99 (0.60-1.64)

1.26 (0.72-2.22)

46 (29.9)

1.25 (0.71-2.20)

1.58 (0.83-3.00)

High

94 (34.9)

58 (30.5)

1.15 (0.70-1.88)

1.23 (0.72-2.10)

49 (31.8)

1.48 (0.85-2.58)

1.57 (0.83-2.94)

Patterns by age at exposure

Teens

<1 hour

18 (6.0)

12 (6.0)

1.00 (reference)

1.00 (reference)

4 (2.5)

1.00 (reference)

1.00 (reference)

Continuous hours

151 (50.0)

113 (56.8)

1.04 (0.45-2.41)

0.97 (0.38-2.48)

96 (60.4)

2.33 (0.69-7.90)

1.76 (0.48-6.47)

Intermittent hours

133 (44.0)

74 (37.2)

1.08 (0.46-2.54)

1.10 (0.42-2.83)

59 (37.1)

2.26 (0.66-7.78)

1.86 (0.50-6.94)

Twenties

<1 hour

34 (11.3)

18 (9.0)

1.00 (reference)

1.00 (reference)

11 (6.9)

1.00 (reference)

1.00 (reference)

Continuous hours

102 (33.9)

91 (45.5)

1.36 (0.68-2.71)

1.58 (0.75-3.36)

74 (46.5)

2.01 (0.86-4.67)

2.99 (1.19-7.48)

Intermittent hours

165 (54.8)

91 (45.5)

1.30 (0.66-2.56)

1.56 (0.74-3.26)

74 (46.5)

2.11 (0.92-4.88)

3.15 (1.27-7.83)

Thirties

<1 hour

60 (20.5)

27 (13.6)

1.00 (reference)

1.00 (reference)

18 (11.3)

1.00 (reference)

1.00 (reference)

Continuous hours

85 (29.0)

79 (39.9)

1.31 (0.72-2.40)

1.77 (0.90-3.49)

69 (43.4)

1.55 (0.77-3.10)

2.25 (1.02-4.94)

Intermittent hours

148 (50.5)

92 (46.5)

1.38 (0.79-2.41)

2.09 (1.11-3.93)

72 (45.3)

1.47 (0.76-2.85)

1.95 (0.92-4.12)

Past 10 years

<1 hour

63 (28.6)

52 (30.2)

1.00 (reference)

1.00 (reference)

49 (33.1)

1.00 (reference)

1.00 (reference)

Continuous hours

74 (33.6)

83 (48.3)

0.88 (0.51-1.52)

1.14 (0.62-2.12)

64 (43.2)

0.81 (0.46-1.42)

1.35 (0.69-2.64)

Intermittent hours

83 (37.7)

37 (21.5)

0.57 (0.32-1.03)

0.67 (0.35-1.28)

35 (23.6)

0.60 (0.33-1.10)

0.93 (0.46-1.89)