Table 5.
Postonset longitudinal 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 | ||||
| Time in sun during week—summer (h/day) | Time in sun during week—winter (h/day) | ||||||
| <1 1 to <2 2 to <3 3 to <4 4+ Trend: |
81/306.27 (0.27) 78/259.86 (0.30) 28/117.64 (0.24) 10/43.55 (0.23) 7/85.85 (0.08) |
1.00 (reference) 1.37 (0.99, 1.89) 1.11 (0.63, 1.96) 1.17 (0.45, 3.05) 0.45 (0.20, 1.02) p = 0.23 |
1.00 (reference) 1.33 (0.96, 1.85) 1.19 (0.70, 2.02) 1.35 (0.49, 3.69) 0.65 (0.28, 1.47) p = 0.93 |
<1 1 to <2 2 to <3 3 to <4 4+ Trend: |
123/439.51 (0.28) 58/225.86 (0.26) 16/55.34 (0.29) 4/32.60 (0.12) 3/59.87 (0.05) |
1.00 (reference) 1.04 (0.75, 1.43) 1.08 (0.60, 1.94) 0.51 (0.22, 1.18) 0.23 (0.08, 0.64) p = 0.013 |
1.00 (reference) 1.05 (0.74, 1.48) 1.14 (0.64, 2.01) 0.70 (0.31, 1.58) 0.38 (0.14, 1.02) p = 0.27 |
| Summer UVR-load during weekdays (kJ/m2) | Winter UVR-load during weekdays (kJ/m2) | ||||||
| 12–41 >41–62 >62–134 >134–422 Trend: |
60/228.55 (0.26) 52/173.53 (0.30) 45/193.22 (0.23) 46/187.89 (0.25) |
1.00 (reference) 1.25 (0.83, 1.87) 1.17 (0.76, 1.81) 1.42 (0.89, 2.27) p = 0.17 |
1.00 (reference) 1.02 (0.67, 1.55) 1.11 (0.70, 1.74) 1.24 (0.75, 2.06) p = 0.40 |
0–7 >7–17 >17–26 >26–198 Trend: |
64/250.24 (0.26) 39/175.02 (0.22) 56/185.92 (0.30) 44/172.02 (0.26) |
1.00 (reference) 0.92 (0.55, 1.53) 1.56 (0.96, 2.54) 1.16 (0.76, 1.77) p = 0.18 |
1.00 (reference) 0.83 (0.49, 1.40) 1.53 (0.92, 2.53) 1.10 (0.70, 1.73) p = 0.27 |
| Time in sun during weekend–summer (h/day) | Time in sun during weekend–winter (h/day) | ||||||
| <1 1 to <2 2 to <3 3 to <4 4+ Trend: |
33/125.95 (0.26) 63/222.71 (0.28) 53/180.29 (0.29) 30/127.79 (0.24) 25/156.42 (0.16) |
1.00 (reference) 1.13 (0.62, 2.06) 1.23 (0.64, 2.36) 1.08 (0.60, 1.95) 0.83 (0.44, 1.56) p = 0.55 |
1.00 (reference) 1.09 (0.63, 1.89) 1.27 (0.71, 2.28) 1.23 (0.69, 2.17) 1.14 (0.62, 2.08) p = 0.47 |
<1 1 to <2 2 to <3 3 to <4 4+ Trend: |
64/219.50 (0.29) 81/311.06 (0.26) 38/133.56 (0.29) 13/71.12 (0.18) 8/77.92 (0.10) |
1.00 (reference) 0.93 (0.62, 1.41) 1.15 (0.75, 1.77) 0.70 (0.37, 1.31) 0.49 (0.21, 1.12) p = 0.12 |
1.00 (reference) 0.97 (0.68, 1.39) 1.25 (0.81, 1.94) 0.99 (0.53, 1.84) 0.83 (0.41, 1.65) p = 0.85 |
| Summer UVR-load during weekend (kJ/m2) | Winter UVR-load during weekends (kJ/m2) | ||||||
| 5–19 >19–50 >50–90 >90–176 Trend: |
51/206.29 (0.25) 62/224.14 (0.28) 51/166.81 (0.31) 39/185.95 (0.21) |
1.00 (reference) 1.23 (0.78, 1.93) 1.47 (0.86, 2.53) 1.45 (0.84, 2.50) p = 0.12 |
1.00 (reference) 1.35 (0.90, 2.03) 1.31 (0.77, 2.22) 1.36 (0.79, 2.34) p = 0.28 |
0–4 >4–9 >9–20 >20–121 Trend: |
52/206.15 (0.25) 43/241.98 (0.18) 59/172.99 (0.34) 49/162.08 (0.30) |
1.00 (reference) 0.77 (0.49, 1.20) 1.49 (0.87, 2.55) 1.41 (0.89, 2.25) p = 0.026 |
1.00 (reference) 0.83 (0.54, 1.26) 1.47 (0.83, 2.60) 1.49 (0.96, 2.33) p = 0.021 |
| Time in sun during holidays—summer (h/day) | Time in sun during holidays—winter (h/day) | ||||||
| <1 1 to <2 2 to <3 3 to <4 4+ Trend: |
35/102.50 (0.34) 53/168.81 (0.31) 44/174.09 (0.25) 39/131.26 (0.30) 32/220.96 (0.15) |
1.00 (reference) 1.11 (0.61, 1.99) 0.94 (0.52, 1.70) 1.00 (0.60, 1.66) 0.63 (0.35, 1.14) p = 0.066 |
1.00 (reference) 1.09 (0.63, 1.87) 1.07 (0.61, 1.85) 1.04 (0.65, 1.66) 0.79 (0.44, 1.41) p = 0.37 |
<1 1 to <2 2 to <3 3 to <4 4+ Trend: |
42/184.50 (0.23) 80/273.80 (0.29) 43/143.75 (0.30) 18/82.71 (0.22) 20/117.13 (0.17) |
1.00 (reference) 1.28 (0.85, 1.93) 1.46 (0.92, 2.30) 0.97 (0.54, 1.73) 0.96 (0.45, 2.02) p = 0.82 |
1.00 (reference) 1.18 (0.77, 1.80) 1.55 (0.97, 2.49) 1.23 (0.69, 2.18) 1.32 (0.66, 2.61) p = 0.21 |
| Summer UVR-load during holidays (kJ/m2) | Winter UVR-load during holidays (kJ/m2) | ||||||
| 3–16 >16–31 >51–64 >64–103 Trend: |
57/201.21 (0.28) 59/206.06 (0.29) 52/183.31 (0.28) 34/177.07 (0.19) |
1.00 (reference) 1.05 (0.72, 1.54) 1.35 (0.83, 2.19) 1.05 (0.57, 1.91) p = 0.56 |
1.00 (reference) 1.13 (0.79, 1.61) 1.30 (0.82, 2.04) 0.97 (0.54, 1.74) p = 0.79 |
0–3 >3–6 >6–14 >14–70 Trend: |
49/217.59 (0.23) 50/207.88 (0.24) 43/181.93 (0.24) 60/163.08 (0.37) |
1.00 (reference) 1.12 (0.74, 1.69) 1.20 (0.74, 1.95) 1.89 (1.26, 2.84) p = 0.006 |
1.00 (reference) 1.14 (0.78, 1.69) 1.22 (0.75, 1.97) 1.89 (1.28, 2.81) p = 0.006 |
Results in bold denote statistical significance (p < 0.05). Results in italics are for tests of trend. Two persons—one each in Queensland and Victoria—did not provide data on sun exposure durations. Three persons—one in Victoria and two in Tasmania—did not provide data on sun exposure durations during the week/weekends but did provide this for holidays. Eight persons—two in Victoria and six in New South Wales—did not provide data on sun exposures during holidays but did provide this for week/weekends.
aAdjusted models for relapse include adjustment for age, sex, and immunomodulatory therapy, and stratified by study site.