Table 2.

Association between caffeine intake per day and the risk of BCC, SCC, and melanoma in the NHS (1984–2008) and the HPFS (1986–2008)

Women (NHS)Men (HPFS)
Caffeine, mgCasesPerson-yearsAge-adjusted RRMV-adjusted RRCasesPerson-yearsAge-adjusted RRMV-adjusted RR
BCC
 Quintile 13,106294,0861.001.001,879136,8191.001.00
 Quintile 23,033292,9910.97 (0.93–1.02)0.97 (0.92–1.01)1,878137,6560.97 (0.91–1.04)0.96 (0.90–1.03)
 Quintile 33,072293,7070.97 (0.92–1.02)0.96 (0.91–1.01)1,895138,1360.96 (0.90–1.02)0.95 (0.89–1.02)
 Quintile 42,765293,8910.93 (0.88–0.98)0.92 (0.87–0.97)1,709138,5430.88 (0.82–0.94)0.87 (0.81–0.93)
 Quintile 52,254294,4900.81 (0.77–0.86)0.82 (0.77–0.86)1,459137,4260.82 (0.76–0.88)0.87 (0.81–0.94)
Ptrend<0.0001<0.0001<0.0001<0.0001
SCC
 Quintile 1222295,6201.001.00171138,5021.001.00
 Quintile 2226294,4551.01 (0.83–1.21)0.96 (0.80–1.16)189139,3831.05 (0.85–1.29)1.03 (0.83–1.28)
 Quintile 3208295,1890.89 (0.74–1.07)0.85 (0.70–1.03)192139,8871.04 (0.84–1.27)0.99 (0.80–1.23)
 Quintile 4195295,2290.95 (0.79–1.15)0.91 (0.75–1.11)198140,0671.10 (0.89–1.34)1.07 (0.86–1.33)
 Quintile 5192295,6521.08 (0.89–1.31)1.03 (0.84–1.26)157138,7360.98 (0.79–1.22)0.91 (0.71–1.15)
Ptrend0.560.810.870.45
Melanoma
 Quintile 178295,7391.001.0077138,5811.001.00
 Quintile 278294,5661.00 (0.73–1.37)1.00 (0.73–1.37)67139,4730.85 (0.61–1.19)0.88 (0.62–1.25)
 Quintile 381295,3131.02 (0.75–1.39)1.04 (0.76–1.43)60139,9990.75 (0.54–1.06)0.86 (0.60–1.23)
 Quintile 477295,3251.00 (0.73–1.37)1.01 (0.73–1.39)71140,1830.90 (0.65–1.24)1.08 (0.76–1.51)
 Quintile 589295,7391.19 (0.88–1.62)1.31 (0.95–1.79)59138,8170.79 (0.56–1.11)0.91 (0.62–1.32)
Ptrend0.250.090.350.93

NOTE: MV-adjusted RR: multivariate-adjusted for BMI (3 groups), physical activity (quintiles), smoking status (never, past, current 1–14 cigarettes per day, 15+ cigarettes per day), childhood reaction to sun, severe sunburns, moles, hair color, family history of melanoma, sun exposures at different age intervals, UV index at birth, age 15, and age 30, and history of nonskin cancer.