Table 1.

Age-adjusted characteristics of participants by categories of baseline annual UV flux (×104 Robertson–Berger units) in the Nurses' Health Study II (1989–2009)

Low (≤110)Medium (111–124)High (≥125)
Number of participants33,99939,48035,282
Age (y)a34.0 (4.7)34.4 (4.7)34.5 (4.6)
Family history of melanoma, %12.511.512.5
Red/blonde hair, %19.519.022.5
Number of moles on legs ≥10, %12.914.815.4
Painful burn/blisters reaction as a child/adolescent, %24.822.925.0
Number of blistering sunburns ≥5 between ages 15 and 20 years, %8.98.712.3
Tanning bed use in early life, %21.627.523.9
Body mass index (kg/m2), mean (SD)24.1 (5.0)24.4 (5.2)23.8 (4.9)
Current smoking, %15.113.511.4
Alcohol intake (g/d), mean (SD)3.3 (6.0)2.6 (5.5)3.6 (6.8)
Physical activity (metabolic equivalent h/wk), mean (SD)25.9 (37.8)23.6 (34.7)25.4 (37.3)
Current rotating night shifts, %60.264.360.1
Menopause status, %1.82.42.8

NOTE: Values are means (SD) or percentages and are standardized to the age distribution of the study population.

  • aValue is not age adjusted.