Table 1.

Age-adjusted means and age-standardized percentages of demographic and clinical characteristics among cases and controls (n= 1,058)

CharacteristicCases (n = 497)Controls (n = 561)P value
Age, y, mean (SE)50 (0.7)50 (0.6)0.55
Gender, % females46430.25
Study site, %0.26
    Philadelphia5053
    San Francisco5047
BMI, kg/m2, mean (SE)25 (0.2)25 (0.2)0.15
BSA,* mean (SE)1.9 (0.01)1.9 (0.01)0.17
Education, %<0.0001
    Before high school2616
    Post high school2925
    College graduate4559
Current smoking status, %0.81
    Yes1414
    No8483
Use vitamins in past year, %0.005
    No3223
    Yes, fairly regularly3333
    Yes, but not regularly2325
Ever pregnant, % yes (among women)85740.001
Family history of melanoma, % any relative840.005
Freckles, %<0.0001
    None to few4365
    Moderate to many5735
Blistering sunburn at any age, % yes7766<0.0001
Skin response after repeated/prolonged exposure, %<0.0001
    Deep tan1627
    Moderate tan4949
    Light tan2819
    Do not tan74
Confirmed dysplastic nevi status, grouped, %<0.0001
    None5189
    ≥14911
Natural eye color, %<0.0001
    Blue/gray/green7966
    Brown2134
Natural hair color, %0.01
    Red/blonde2719
    Brown/red-brown/black7381
  • NOTE: Some percentages do not add up to 100% due to missing data.

  • * BSA calculated by Embedded Image.