Table 3

 Multiple logistic regression comparison of cases with controls for iris colour, skin sun sensitivity, and sun exposure as risk factors for AMD

Odds ratio (95% CI)
All cases (n = 430)v controls (n = 280)All CNV cases (n = 324) v controls (n = 280)All GA cases (n = 172)v controls (n = 280)
*Denotes reference category.
Age
    Per year increment1.09 (1.07 to 1.12)1.09 (1.06 to 1.12)1.12 (1.08 to 1.16)
p Value (two tailed) for age<0.0001<0.0001<0.0001
Sex
    Male*1.001.001.00
    Female1.06 (0.73 to 1.53)1.09 (0.74 to 1.61)1.13 (0.70 to 1.83)
p Value (two tailed) for sex0.770.670.62
Iris colour
    Dark*1.001.001.00
    Light0.86 (0.52 to 1.42)0.75 (0.45 to 1.26)1.56 (0.75 to 3.25)
p Value (two tailed) for iris colour0.560.270.23
Change in iris colour
    Same*1.001.001.00
    Lighter1.36 (0.87 to 2.12)1.29 (0.81 to 2.07)1.38 (0.77 to 2.46)
    Darker1.19 (0.64 to 2.25)1.11 (0.57 to 2.16)1.64 (0.75 to 3.60)
p Value (two tailed) for change in iris colour0.370.560.31
Worked/lived in sunny climate for ⩾5 years
    No*1.001.001.00
    Yes1.18 (0.74 to 1.89)1.19 (0.72 to 1.95)1.30 (0.73 to 2.33)
p Value (two tailed) for sunny climate abroad0.500.500.38
Treatment for skin tumour
    No*1.001.001.00
    Yes0.97 (0.48 to 1.98)1.06 (0.50 to 2.24)0.85 (0.32 to 2.23)
p Value (two tailed) for skin tumour0.940.880.74
Skin sun sensitivity (skin type)
    Sunburn resistant*1.001.001.00
    Sunburn prone1.24 (0.85 to 1.80)1.14 (0.76 to 1.70)1.62 (1.01 to 2.61)
p Value (two tailed) for skin sun sensitivity0.270.530.05
Hair colour
    Dark*1.001.001.00
    Light1.19 (0.80 to 1.76)1.25 (0.83 to 1.89)1.26 (0.75 to 2.11)
p Value (two tailed) for hair colour0.390.290.38
Sun exposure index
    Per unit increment1.00 (0.99 to 1.00)1.00 (0.99 to 1.00)1.00 (0.99 to 1.00)
p Value (two tailed) for sun exposure0.420.440.29
Sun avoidance measures undertaken
    Yes*1.001.001.00
    No1.00 (0.58 to 1.72)0.94 (0.53 to 1.68)1.14 (0.57 to 2.30)
p Value (two tailed) for sun avoidance1.000.840.71
Pack years of smoking
    0*1.001.001.00
    0.1–200.82 (0.55 to 1.21)0.76 (0.50 to 1.15)0.84 (0.50 to 1.40)
    20.1–401.60 (0.99 to 2.52)1.46 (0.90 to 2.39)1.74 (0.96 to 3.16)
    >402.68 (1.36 to 5.29)2.42 (1.19 to 4.92)3.60 (1.59 to 8.18)
p Value (two tailed) for pack years0.0010.0030.001