Table 1.
Baseline characteristics according to clinical categories for 25-hydroxyvitamin D plasma levels
*Afzal et al., J Invest Dermatol. 2013 ;133:629–36 - reproduced with permission5
| Plasma 25-hydroxyvitamin D (nmoll−1) | Non-melanoma skin cancer | Melanoma | ||||||
|---|---|---|---|---|---|---|---|---|
| <25 (n = 2,362) | 25–49.9 (n = 4,035) | >50 (n = 3,663) | P-value1 | HR (95% CI) | P-value2 | HR (95% CI) | P-value2 | |
| Men, no. (%) | 1,074 (45) | 1,760 (44) | 1,575 (43) | 0.07 | 1.26 (1.07–1.49) | 0.007 | 1.47 (0.94–2.30) | 0.09 |
| Age, years | <0.001 | <0.001 | 0.13 | |||||
| Median | 59 | 59 | 57 | |||||
| Interquartile range | 50–65 | 49–65 | 48–65 | |||||
| Cumulative tobacco consumption, pack-years | <0.001 | 1.00 (0.99–1.00) | 0.84 | 0.99 (0.98–1.01) | 0.82 | |||
| Median | 24 | 19 | 18 | |||||
| Interquartile range | 10–38 | 5–33 | 3–31 | |||||
| Body mass index, kg m−2 | <0.001 | 0.98 (0.96–1.00) | 0.04 | 0.98 (0.93–1.04) | 0.60 | |||
| Median | 25 | 25 | 24 | |||||
| Interquartile range | 23–29 | 23–28 | 22–27 | |||||
| Income group, no. (%)3 | <0.001 | <0.001 | 0.55 | |||||
| Low (<84,000 DKr) | 927 (40) | 1,262 (32) | 974 (27) | 1 | 1 | |||
| Medium (84,000–192,000 DKr) | 1,031 (44) | 1,874 (47) | 1,714 (47) | 1.15 (0.93–1.43) | 1.43 (0.77–2.66) | |||
| High (>192,000 DKr) | 368 (16) | 844 (21) | 941 (26) | 1.57 (1.23–2.00) | 1.28 (0.62–2.65) | |||
| Occupational physical exertion, no. (%) | 0.074 | 0.064 | 0.354 | |||||
| Low | 798 (34) | 1,363 (34) | 1,273 (35) | 1 | 1 | |||
| Occasional | 864 (37) | 1,596 (40) | 1,480 (40) | 0.76 (0.63–0.92) | 1.06 (0.61–1.84) | |||
| Moderate | 510 (22) | 858 (21) | 752 (21) | 0.88 (0.70–1.10) | 1.36 (0.75–2.50) | |||
| High | 108 (5) | 141 (3) | 111 (3) | 0.68 (0.40–1.16) | 1.23 (0.36–4.15) | |||
| Without work | 82 (3) | 77 (2) | 47 (1) | — | — | |||
| Leisure-time activities, hours per week2 | <0.001 | 0.08 | 0.03 | |||||
| ⩽2 | 598 (25) | 686 (17) | 410 (11) | 1 | 1 | |||
| 2–4 (light activity) | 1,115 (47) | 1,986 (49) | 1,792 (49) | 1.14 (0.88–1.47) | 0.89 (0.43–1.81) | |||
| 2–4 (heavy activity) or ⩾4 (light activity) | 622 (26) | 1,282 (32) | 1,346 (37) | 1.25 (0.96–1.63) | 1.61 (0.96–1.63) | |||
| ⩾4 (heavy activity) | 27 (1) | 79 (2) | 115 (3) | 1.36 (0.75–2.46) | 1.87 (0.50–7.03) | |||
| Regular cycling or running | <0.001 | <0.001 | 0.02 | |||||
| No | 1,545 (65) | 2,274 (56) | 1,774 (48) | 1 | 1 | |||
| Yes | 817 (35) | 1,761 (44) | 1,889 (52) | 1.36 (1.15–1.61) | 1.75 (1.10–2.80) | |||
Abbreviations: CI, confidence interval; HR, hazard ratio.
1
P-values were calculated using Cuzick’s non-parametric trend test.
2
Trend test or use of continuous variable, Cox regression.
3
1981–1983 income levels (1 US$ ∼6 DKr).
4
Excluding participants not working. The following covariates had missing values: income group: 125 observations, leisure-time activities: 2 observations, and body mass index: 18 observations.