Table 1 Demographic characteristics and selected risk factors for cases and controls
Characteristic | Cases (n = 413) | Controls (n = 263) |
|---|---|---|
Male (%) | 36 | 42 |
Female (%) | 64 | 58 |
Median age in years1 (median, IQR) | 33 (28–37) | 35 (31–39) |
European ancestry (%) | Â | Â |
  British or northern European | 75 | 60 |
  Southern European | 4 | 7 |
  Other European or unknown | 21 | 33 |
MC1R (%) | Â | Â |
  Wild-type consensus alleles only | 15 | 29 |
  r only alleles | 27 | 32 |
  Any R allele | 58 | 40 |
Number of nevi ≥ 2 mm (median, IQR) | 205 (108–320) | 67 (28–158) |
Number of dysplastic nevi (%) | Â | Â |
  0 | 55 | 76 |
  1 | 11 | 11 |
  2+ | 34 | 13 |
Previous non-melanoma skin cancer (%) | 8 | 2 |
Confirmed family history of melanoma (%) | 10 | 5 |
Pigmentation score, self-reported (%) | Â | Â |
  1st quartile (lower risk) | 8 | 24 |
  2nd quartile | 26 | 26 |
  3rd quartile | 24 | 25 |
  4th quartile (higher risk) | 42 | 25 |
Number of childhood blistering sunburns (%) | Â | Â |
  0 | 65 | 69 |
  ≤ 8 | 17 | 19 |
  > 8 | 18 | 12 |
Number of lifetime sunbed sessions (%) | Â | Â |
  0 | 76 | 80 |
  1–10 | 14 | 14 |
  > 10 | 10 | 6 |