Table 4.
The association between smoking and SCC in HPFS and NHS
| Men (HPFS) |
Women (NHS) |
|||||||
|---|---|---|---|---|---|---|---|---|
| Smoking variables | Cases | Person years | Age-adjusted RR | Multivariable-adjusted RR | Cases | Person years | Age-adjusted RR | MV-adjusted RR |
| Smoking status | ||||||||
| Never | 440 | 303 318 | 1.00 | 1.00 | 561 | 1 308 051 | 1.00 | 1.00 |
| Past smoker | 484 | 308 595 | 0.92 (0.81–1.05) | 0.93 (0.82–1.06) | 596 | 1 017 034 | 1.16 (1.03–1.30) | 1.11 (0.98–1.24) |
| Current smoker | 67 | 46 401 | 1.15 (0.89–1.49) | 1.31 (1.01–1.70) | 182 | 551 844 | 1.34 (1.13–1.58) | 1.38 (1.16– 1.64) |
| Ever smoker | 551 | 354 996 | 0.95 (0.84–1.06) | 0.99 (0.89–1.12) | 778 | 1 568 878 | 1.21 (1.09–1.32) | 1.19 (1.08–1.31) |
| Duration of smoking | ||||||||
| Never | 440 | 303 318 | 1.00 | 1.00 | 561 | 1 308 051 | 1.00 | 1.00 |
| <20 years | 279 | 167 100 | 1.06 (0.91–1.23) | 1.10 (0.94–1.28) | 285 | 636 498 | 1.22 (1.06–1.41) | 1.12 (0.97–1.30) |
| 20–29 years | 82 | 72 230 | 0.75 (0.60–0.96) | 0.74 (0.58–0.94) | 137 | 395 828 | 1.07 (0.89–.29) | 1.05 (0.87–1.27) |
| 30+ years | 167 | 99 217 | 0.91 (0.76–1.09) | 0.92 (0.77–1.11) | 356 | 536 552 | 1.23 (1.07–1.40) | 1.24 (1.08–1.42) |
| P for trend | 0.06 | 0.08 | 0.008 | 0.005 | ||||
| Daily smoking in current smokers | ||||||||
| Never | 440 | 303 318 | 1.00 | 1.00 | 561 | 1 308 051 | 1.00 | 1.00 |
| 1–14 daily | 31 | 14 823 | 1.52 (1.06–2.20) | 1.68 (1.16–2.43) | 69 | 177 072 | 1.24 (0.96–1.59) | 1.21 (0.94–1.56) |
| 15+ daily | 28 | 23 991 | 0.97 (0.66–1.43) | 1.03 (0.70–1.52) | 112 | 368 086 | 1.45 (1.18–1.78) | 1.54 (1.25–1.89) |
| P for trend | 0.46 | 0.42 | 0.0004 | 0.0003 | ||||
| Pack years for smokers | ||||||||
| Never | 440 | 303 318 | 1.00 | 1.00 | 561 | 1 308 051 | 1.00 | 1.00 |
| <10 years | 93 | 65 892 | 0.97 (0.78–1.21) | 0.99 (0.79–1.25) | 237 | 494 457 | 1.22 (1.04–1.42) | 1.12 (0.96–1.31) |
| 10–24 years | 208 | 125 684 | 1.05 (0.89–1.24) | 1.09 (0.92–1.28) | 200 | 463 112 | 1.15 (0.98–1.35) | 1.10 (0.93–1.29) |
| 25–44 years | 131 | 91 742 | 0.84 (0.69–1.02) | 0.84 (0.69–1.02) | 199 | 394 961 | 1.24 (1.05–1.45) | 1.24 (1.06–1.46) |
| >45 years | 94 | 51 848 | 0.95 (0.76–1.19) | 0.94 (0.75–1.18) | 142 | 216 347 | 1.17 (0.97–1.41) | 1.19 (0.99–1.44) |
| P for trend | 0.34 | 0.28 | 0.07 | 0.02 | ||||
| Years since quitting in past smokers | ||||||||
| Never | 440 | 303 318 | 1.00 | 1.00 | 561 | 1 308 051 | 1.00 | 1.00 |
| 10+ years | 416 | 246 695 | 0.93 (0.81–1.07) | 0.93 (0.81–1.07) | 486 | 726 092 | 1.19 (1.05–1.34) | 1.12 (0.99–1.27) |
| <10 years | 64 | 59 760 | 0.85 (0.66–1.11) | 0.90 (0.69–1.18) | 110 | 290 942 | 1.04 (0.85–1.28) | 1.04 (0.85–1.28) |
MV-adjusted RR: multivariable adjusted for body mass index; physical activity (quintiles); history of cardiovascular diseases, such as type 2 diabetes, hypertension, hypercholesterolaemia and non-skin cancer; childhood reaction to sun; severe sunburns; moles; hair colour; family history of melanoma; sun exposures at different age intervals; UV index at birth, age 15 and age 30 years.