Table 9.
Distribution of sun/vitamin D behavioral variables during study relative to MS conversion. Table restricted to those who converted to MS and who were followed up to 5-year review.
| Baseline | Postentry, prior to MS conversion | Post-MS conversion | 5-Year review | Test for difference by Chi-square test | |
|---|---|---|---|---|---|
| Summer weekday UVR-load (kJ/m2) | |||||
| 12–41 >41–62 >62–134 >134–422 |
57 (59.4%) 17 (17.7%) 16 (16.7%) 6 (6.3%) |
11 (18.6%) 14 (23.7%)* 20 (33.9%)** 14 (23.7%)** |
50 (18.5%) 73 (26.9%)** 69 (25.5%)** 79 (29.2%)** |
10 (10.0%) 31 (31.0%)** 33 (33.0%)** 26 (26.0%)** |
p < 0.001 |
| Summer weekend UVR-load (kJ/m2) | |||||
| 5–19 >19–50 >50–90 >90–176 |
46 (47.9%) 41 (42.7%) 5 (5.2%) 4 (4.2%) |
7 (11.9%) 19 (32.2%)* 22 (37.3%) 11 (18.6%) |
62 (22.9%) 53 (19.6%)** 85 (31.4%)** 71 (26.2%)** |
20 (20.0%) 12 (12.0%)** 39 (39.0%)** 29 (29.0%)** |
p < 0.001 |
| Summer holiday UVR-load (kJ/m2) | |||||
| 3–16 >16–31 >31–64 >64–103 |
43 (47.3%) 36 (39.6%) 9 (9.9%) 3 (3.3%) |
7 (11.9%) 16 (27.1%)* 26 (44.1%) 10 (17.0%) |
63 (23.5%) 56 (20.9%)** 72 (26.9%)** 77 (28.7%)** |
18 (18.0%) 21 (21.0%)** 33 (33.0%)** 28 (28.0%)** |
p < 0.001 |
| Winter weekday UVR-load (kJ/m2) | |||||
| 0–7 >7–17 >17–26 >26–198 |
59 (61.5%) 18 (18.8%) 7 (7.3%) 12 (12.5%) |
16 (27.1%) 8 (13.6%) 22 (37.3%)** 13 (22.0%)** |
53 (19.6%) 79 (29.2%)** 68 (25.1%)** 71 (26.2%)** |
16 (16.0%) 27 (27.0%)** 28 (28.0%)** 29 (29.0%)** |
p < 0.001 |
| Winter weekend UVR-load (kJ/m2) | |||||
| 0–4 >4–9 >9–20 >20–121 |
46 (47.9%) 36 (37.5%) 11 (11.5%) 3 (3.1%) |
11 (18.6%) 15 (25.4%) 15 (25.4%) 18 (30.5%)* |
61 (22.5%) 76 (28.0%)* 73 (26.9%)** 61 (22.5%)** |
12 (12.0%) 25 (25.0%)** 29 (29.0%)** 34 (34.0%)** |
p < 0.001 |
| Winter holiday UVR-load (kJ/m2) | |||||
| 0–3 >3–6 >6–14 >14–70 |
44 (48.4%) 26 (28.6%) 17 (18.7%) 4 (4.4%) |
8 (15.1%) 18 (34.0%)* 9 (17.0%) 18 (34.0%) |
66 (26.3%) 60 (23.9%) 64 (25.5%)* 61 (24.3%)** |
16 (16.2%) 19 (19.2%)** 32 (32.3%)** 32 (32.3%)** |
p < 0.001 |
| Taking vitamin D-containing supplement at review? | |||||
| No Yes |
75 (75.0%) 25 (25.0%) |
46 (74.2%) 16 (25.8%) |
201 (73.1%) 74 (26.9%) |
56 (56.0%) 44 (44.0%)* |
p = 0.006 |
| Taking high-dose (1,000 IU +) vitamin D-containing supplement at review? | |||||
| No Yes |
98 (98.0%) 2 (2.0%) |
60 (96.8%) 2 (3.2%) |
243 (88.4%) 32 (11.6%)* |
61 (61.0%) 39 (39.0%)** |
p < 0.001 |
Test for difference of strata by review assessed by multinomial logistic regression.
Results in bold denote statistical significance (p < 0.05). Results in italics are for tests of trend.
*p < 0.05.
**p < 0.001.
UVR, ultraviolet radiation.