Table 2.
Association of Tea Consumption and SCC risk
| Exposure | Cases n (%)N=415 | Controls n (%)N=415 | Crude OR (95%CI) | Parsimoniously Adjusted OR1 (95% CI) | Fully Adjusted OR2 (95% CI) |
|---|---|---|---|---|---|
| Overall use | |||||
| Not regular3 | 271 (65.3) | 278 (67.0) | 1.0 (referent) | 1.0 (referent) | 1.0 (referent) |
| Regular | 144 (34.7) | 137 (33.0) | 1.08 (0.81, 1.44) | 1.11 (0.80, 1.54) | 1.20 (0.82, 1.75) |
| Dose (cups)4 | |||||
| None | 271(65.3) | 278 (67.0) | 1.0 (referent) | 1.0 (referent) | 1.0 (referent) |
| < 1 per day | 60 (14.5) | 53 (12.8) | 1.17 (0.77, 1.79) | 1.10 (0.68, 1.77) | 1.22 (0.71, 2.11) |
| 1 per day | 42 (10.1) | 37 (8.9) | 1.15 (0.73, 1.83) | 1.24 (0.73, 2.12) | 1.48 (0.81, 2.73) |
| >1 per day | 42 (10.1) | 47 (11.3) | 0.91 (0.58, 1.44) | 1.00 (0.60, 1.67) | 0.98 (0.55, 1.73) |
| Test for Trend | p-value 0.70 | p-value 0.88 | p-value 0.89 | ||
| Duration (years)4 | |||||
| None | 271(65.3) | 278 (67.0) | 1.0 (referent) | 1.0 (referent) | 1.0 (referent) |
| 1–4 | 44 (10.6) | 44 (10.6) | 1.03 (0.66, 1.59) | 1.03 (0.63, 1.70) | 1.20 (0.67, 2.13) |
| 5–14 | 39 (9.4) | 34 (8.2) | 1.19 (0.72, 1.99) | 1.30 (0.73, 2.28) | 1.29 (0.67, 2.47) |
| ≥ 15 | 61 (14.7) | 59 (14.2) | 1.06 (0.71, 1.58) | 1.06 (0.66, 1.68) | 1.14 (0.67, 1.95) |
| Test for Trend | p-value 0.64 | p-value 0.62 | p-value 0.60 | ||
| Cup-Years4,5 | |||||
| 0 | 271 (65.3) | 278 (67.0) | 1.0 (referent) | 1.0 (referent) | 1.0 (referent) |
| >0 to ≤ 3 | 52 (12.5) | 50 (12.1) | 1.07 (0.70, 1.62) | 1.08 (0.68, 1.88) | 1.26 (0.73, 2.17) |
| >3 to ≤ 10 | 41 (9.9) | 36 (8.7) | 1.17 (0.72, 1.90) | 1.06 (0.60, 1.86) | 1.14 (0.60, 2.19) |
| > 10 | 51 (12.3) | 51 (12.3) | 1.03 (0.68, 1.57) | 1.16 (0.72, 1.74) | 1.18 (0.68, 2.03) |
| Test for Trend | p-value 0.80 | p-value 0.61 | p-value 0.68 | ||
Adjusted for variables associated with both tea exposure and SCC risk at the p<0.20 level including eye color (blue/grey vs. other), natural hair color (red/blond vs. other), skin type (reaction of skin after exposure to 1 hour of mid-day sun for the first time in the summer with 1=painful or blistering sunburn with no tan, 2=painful sunburn followed by a light tan, 3= mild sunburn followed by a moderate tan, 4= no sunburn followed by a deep tan), education (4-year college or above vs. not), history of sunburns (> 2 severe vs. ≤ 2 severe), regular (at least once-a-week for at least 2 hours) peak-time sun exposure (yes/no), and history of smoking (current vs. former/none). Dummy variables were created for all missing values. 95% CI values are Wald estimates.
Adjusted for all SCC risk factors including eye color (blue/grey vs. other), natural hair color (red/blond vs. other), skin type (reaction of skin after exposure to 1 hour of mid-day sun for the first time in the summer with 1=painful or blistering sunburn with no tan, 2=painful sunburn followed by a light tan, 3= mild sunburn followed by a moderate tan, 4= no sunburn followed by a deep tan), education (4-year college or above vs. not), history of sunburns (> 2 severe vs. ≤ 2 severe), history of high-risk exposures such as UV light, burn scar, non-healing ulcers, radiation treatment, arsenic exposure, exposure to industrial chemicals (yes/no), history of smoking (current vs. former/none), history of freckling (yes/no), outdoor sun exposure (> 2 hours per week between 10am and 4 pm) (yes/no), occupational sun exposure (yes/no), tanning bed use (yes/no), and family history of skin cancer (yes/no). Dummy variables were created for all missing values. 95% CI values are Wald estimates.
Less than once/week for one year
Test for trend is not significant (all p-values > 0.60)
Number of cups per week × years of use using the midpoint of each dose and duration category, and the lower bound for top categories