Table 2: Hazard ratios for melanoma, squamous cell carcinoma, and basal cell carcinoma according to cumulative UV flux

From: Cumulative ultraviolet radiation flux in adulthood and risk of incident skin cancers in women

 No. of cases (%)Age-adjusted HR (95%CI)Multivariable HR (95%CI)a
Melanoma (n=634 cases)
UV flux Q1b88 (14)0.66 (0.30, 1.47)0.85 (0.36, 2.01)
UV flux Q2130 (21)1.07 (0.58, 1.96)1.32 (0.68, 2.55)
UV flux Q3112 (18)0.89 (0.56, 1.41)1.02 (0.63, 1.67)
UV flux Q4129 (20)1.01 (0.74, 1.38)1.07 (0.78, 1.47)
UV flux Q5175 (28)1.001.00
P for trend0.680.77
Per 200 × 10−4 RB units increasec1.004 (0.966, 1.044)0.979 (0.933, 1.028)
Squamous cell carcinoma (n=1065 cases)
UV flux Q1b7 (1)0.04 (0.01, 0.29)0.05 (0.01, 0.35)
UV flux Q269 (6)0.29 (0.17, 0.48)0.34 (0.20, 0.59)
UV flux Q3162 (15)0.51 (0.37, 0.69)0.57 (0.40, 0.79)
UV flux Q4272 (26)0.70 (0.57, 0.85)0.74 (0.60, 0.91)
UV flux Q5555 (52)1.001.00
P for trend<0.0001<0.0001
Per 200 × 10−4 RB units increasec1.069 (1.046, 1.092)1.072 (1.041, 1.103)
Basal cell carcinoma (n=15 159 cases)
UV flux Q1b152 (1)0.41 (0.33, 0.52)0.47 (0.37, 0.59)
UV flux Q22640 (17)0.40 (0.36, 0.44)0.45 (0.40, 0.51)
UV flux Q33505 (23)0.59 (0.54, 0.64)0.64 (0.58, 0.70)
UV flux Q43819 (25)0.81 (0.76, 0.85)0.84 (0.79, 0.89)
UV flux Q55043 (33)1.001.00
P for trend<0.0001<0.0001
Per 200 × 10−4 RB units increasec1.052 (1.045, 1.059)1.043 (1.034, 1.052)
  1. Abbreviations: CI=confidence interval; HR=hazard ratio; UV=ultraviolet.
  2. aMultivariable analyses adjusted for age, susceptibility to burn, ability to tan, natural hair colour at age 20, number of moles on left arm, family history of melanoma, severe sunburn counts, UV indices at state of residence at birth, 15 and 30 years of age, physical activity level, and rotating night shift.
  3. bUV flux quintiles: Q1=200–656, Q2=678–1294, Q3=1296–1872, Q4=1874–2614, and Q5=2616–5392 × 10−4 RB units, respectively.
  4. cCumulative UV flux was modelled as a continuous variable in the models.