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. 2018 Feb 1;9:16. doi: 10.3389/fneur.2018.00016

Table 3.

Preonset sun exposure measures and associations with relapse hazard.

Summer UVR measures and relapse hazard Winter UVR measures and relapse hazard
Failures/person-years (rate) HR (95% CI)
 Failures/person-years (rate) HR (95% CI)
Univariable Adjusteda Univariable Adjusteda
Summer UVR-load 6–10 years old (kJ/m2) Winter UVR-load 6–10 years old (kJ/m2)
0–228
>228–323
>323–383
>383–488
Trend:		 66/235.56 (0.28)
77/262.48 (0.29)
40/220.65 (0.18)
24/173.87 (0.14)		 1.00 (reference)
1.16 (0.66, 2.06)
0.87 (0.51, 1.50)
0.48 (0.28, 0.83)
p = 0.006 		1.00 (reference)
1.11 (0.70, 1.77)
0.92 (0.59, 1.42)
0.54 (0.34, 0.87)
p = 0.010 		0–31
>31–52
>52–100
>100–544
Trend:		 59/231.23 (0.26)
51/258.75 (0.20)
47/215.54 (0.22)
50/187.05 (0.27)		 1.00 (reference)
0.75 (0.46, 1.24)
0.82 (0.43, 1.55)
0.76 (0.40, 1.45)
p = 0.44 		1.00 (reference)
0.81 (0.51, 1.27)
0.97 (0.59, 1.58)
0.83 (0.45, 1.53)
p = 0.68
Summer UVR-load 11–15 years old (kJ/m2) Winter UVR-load 11–15 years old (kJ/m2)
0–229
>229–313
>313–360
>360–482
Trend:		 66/234.11 (0.28)
76/229.39 (0.33)
39/259.77 (0.15)
26/169.30 (0.15)		 1.00 (reference)
1.22 (0.70, 2.14)
0.70 (0.43, 1.14)
0.55 (0.29, 1.08)
p = 0.015 		1.00 (reference)
1.26 (0.78, 2.02)
0.85 (0.56, 1.30)
0.67 (0.38, 1.19)
p = 0.072 		0–33
>33–53
>53–104
>104–530
Trend:		 61/237.34 (0.26)
48/235.30 (0.20)
43/218.56 (0.20)
55/201.37 (0.27)		 1.00 (reference)
0.73 (0.45, 1.18)
0.73 (0.39, 1.36)
0.76 (0.42, 1.38)
p = 0.39 		1.00 (reference)
0.70 (0.45, 1.09)
0.81 (0.50, 1.30)
0.87 (0.50, 1.49)
p = 0.76
Summer UVR-load 16–20 years old (kJ/m2) Winter UVR-load 16–20 years old (kJ/m2)
0–188
>188–266
>266–337
>337–491
Trend:		 75/232.69 (0.32)
63/222.79 (0.28)
43/244.31 (0.18)
26/192.78 (0.14)		 1.00 (reference)
0.94 (0.52, 1.72)
0.70 (0.42, 1.16)
0.51 (0.24, 1.07)
p = 0.028 		1.00 (reference)
0.95 (0.54, 1.66)
0.85 (0.53, 1.35)
0.79 (0.41, 1.51)
p = 0.38 		0–28
>28–45
>45–80
>80–556
Trend:		 78/239.42 (0.33)
52/254.66 (0.20)
45/192.52 (0.23)
32/205.97 (0.16)		 1.00 (reference)
0.70 (0.42, 1.15)
0.73 (0.36, 1.45)
0.42 (0.24, 0.71)
p = 0.002 		1.00 (reference)
0.73 (0.48, 1.12)
0.82 (0.43, 1.54)
0.62 (0.39, 0.98)
p = 0.078
Summer UVR-load 21–25 years old (kJ/m2) Winter UVR-load 21–26 years old (kJ/m2)
0–148
>148–237
>237–329
>329–494
Trend:		 60/194.49 (0.31)
36/196.10 (0.18)
63/210.98 (0.30)
33/227.37 (0.15)		 1.00 (reference)
0.66 (0.37, 1.16)
1.07 (0.59, 1.95)
0.56 (0.29, 1.09)
p = 0.29 		1.00 (reference)
0.78 (0.51, 1.18)
1.37 (0.83, 2.26)
1.06 (0.61, 1.86)
p = 0.36 		0–24
>24–44
>44–85
>85–285
Trend:		 66/230.68 (0.29)
51/207.96 (0.25)
19/197.42 (0.10)
56/192.87 (0.29)		 1.00 (reference)
0.96 (0.55, 1.66)
0.34 (0.17, 0.65)
0.79 (0.45, 1.37)
p = 0.19 		1.00 (reference)
1.16 (0.73, 1.83)
0.50 (0.27, 0.92)
1.11 (0.68, 1.81)
p = 0.98
Summer UVR-load 26–30 years old (kJ/m2) Winter UVR-load 26–30 years old (kJ/m2)
0–143
>143–228
>228–329
>329–510
Trend:		 50/168.47 (0.30)
43/214.71 (0.20)
43/160.88 (0.27)
25/218.57 (0.11)		 1.00 (reference)
0.68 (0.40, 1.17)
0.89 (0.41, 1.91)
0.45 (0.24, 0.86)
p = 0.093 		1.00 (reference)
0.89 (0.51, 1.54)
1.25 (0.61, 2.56)
1.00 (0.47, 2.11)
p = 0.69 		0–21
>21–44
>44–70
>70–411
Trend:		 46/218.58 (0.21)
51/198.80 (0.26)
25/204.45 (0.12)
39/140.81 (0.28)		 1.00 (reference)
1.22 (0.73, 2.04)
0.46 (0.26, 0.82)
0.90 (0.44, 1.82)
p = 0.35 		1.00 (reference)
1.45 (0.89, 2.37)
0.75 (0.42, 1.32)
1.22 (0.65, 2.29)
p = 0.87
Summer UVR-load 31–35 years old (kJ/m2) Winter UVR-load 31–35 years old (kJ/m2)
0–136
>136–218
>218–328
>328–465
Trend:		 37/156.09 (0.24)
22/165.80 (0.13)
43/187.47 (0.23)
21/149.85 (0.14)		 1.00 (reference)
0.53 (0.27, 1.05)
0.99 (0.46, 2.10)
0.68 (0.35, 1.31)
p = 0.72 		1.00 (reference)
0.71 (0.39, 1.27)
1.36 (0.69, 2.67)
1.49 (0.69, 3.21)
p = 0.20 		0–22
>22–37
>37–69
>69–214
Trend:		 34/200.37 (0.17)
25/167.84 (0.15)
32/163.86 (0.20)
32/127.14 (0.25)		 1.00 (reference)
0.98 (0.52, 1.84)
0.92 (0.49, 1.72)
0.97 (0.42, 2.23)
p = 0.89 		1.00 (reference)
1.20 (0.66, 2.17)
1.18 (0.61, 2.27)
1.75 (0.75, 4.10)
p = 0.26
Summer UVR-load in 3 years before study entryb (kJ/m2) Winter UVR-load in 3 years before study entry (kJ/m2)
0–80
>80–90
>90–152
>152–290
Trend:		 35/214.68 (0.16)
92/209.96 (0.44)
42/201.44 (0.21)
35/252.72 (0.14)		 1.00 (reference)
2.28 (1.31, 3.97)
1.24 (0.75, 2.03)
0.87 (0.44, 1.72)
p = 0.14 		1.00 (reference)
2.43 (1.50, 3.95)
1.31 (0.83, 2.08)
1.26 (0.65, 2.45)
p = 0.77 		0–17
>17–27
>27–41
>41–125
Trend:		 54/247.55 (0.22)
49/210.32 (0.23)
52/202.49 (0.26)
49/218.43 (0.22)		 1.00 (reference)
0.70 (0.40, 1.23)
0.80 (0.36, 1.77)
0.62 (0.25, 1.51)
p = 0.36 		1.00 (reference)
0.94 (0.61, 1.45)
1.15 (0.53, 2.46)
1.05 (0.43, 2.58)
p = 0.89
UVR-load in summer in year of FDE (kJ/m2) UVR-load in winter in year of FDE (kJ/m2)
7–28
>28–47
>47–69
>69–96
Trend:		 55/198.76 (0.28)
51/214.40 (0.24)
66/249.43 (0.27)
28/189.82 (0.15)		 1.00 (reference)
0.89 (0.52, 1.54)
1.08 (0.61, 1.90)
0.60 (0.34, 1.07)
p = 0.23 		1.00 (reference)
1.02 (0.68, 1.53)
1.43 (0.86, 2.38)
1.05 (0.58, 1.91)
p = 0.42 		1–5
>5–9
>9–14
>14–53
Trend:		 72/232.12 (0.31)
32/220.90 (0.15)
39/210.57 (0.19)
57/188.82 (0.30)		 1.00 (reference)
0.48 (0.29, 0.81)
0.54 (0.27, 1.09)
0.69 (0.38, 1.25)
p = 0.25 		1.00 (reference)
0.65 (0.42, 1.02)
0.83 (0.43, 1.59)
1.17 (0.66, 2.09)
p = 0.62
UVR-load in summer 2 years before FDE (kJ/m2) UVR-load in winter 2 years before FDE (kJ/m2)
7–28
>28–50
>50–69
>69–96
Trend:		 55/193.88 (0.28)
64/227.79 (0.28)
52/241.93 (0.22)
33/206.86 (0.16)		 1.00 (reference)
1.00 (0.56, 1.77)
0.88 (0.52, 1.49)
0.63 (0.35, 1.15)
p = 0.12 		1.00 (reference)
1.10 (0.68, 1.78)
1.14 (0.73, 1.77)
0.95 (0.55, 1.63)
p = 0.96 		1–5
>5–9
>9–14
>14–53
Trend:		 64/251.92 (0.25)
39/212.00 (0.18)
39/21.68 (0.18)
62/184.86 (0.34)		 1.00 (reference)
0.73 (0.41, 1.32)
0.69 (0.35, 1.34)
1.04 (0.58, 1.85)
p = 0.90 		1.00 (reference)
0.92 (0.58, 1.45)
0.96 (0.52, 1.77)
1.43 (0.83, 2.46)
p = 0.26

Results in bold denote statistical significance (p < 0.05). Results in italics are for tests of trend.

aAdjusted models for relapse include adjustment for age, sex, and immunomodulatory therapy, and stratified by study site.

bTwo persons did not have data on their summer UVR-load in the 3 years preceding study entry.