Table II.
Association between indoor tanning use in early life and smoking, alcohol consumption, and coffee intake*
| Times/y tanning | Age-adjusted OR (95% CI) | Multivariate† OR (95% CI) | Multivariate‡ OR (95% CI) |
|---|---|---|---|
|
| |||
| Past smoker* vs never smoker | |||
| Never | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| 1–2 | 1.29 (1.23–1.36) | 1.28 (1.22–1.35) | 1.26 (1.19–1.33) |
| 3–11 | 1.35 (1.26–1.44) | 1.33 (1.25–1.43) | 1.29 (1.20–1.40) |
| 12+ | 1.54 (1.37–1.73) | 1.51 (1.34–1.70) | 1.42 (1.24–1.63) |
| P-trend | <.0001 | <.0001 | <.0001 |
| Current smoker* vs never smoker | |||
| Never | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| 1–2 | 1.36 (1.27–1.44) | 1.36 (1.27–1.45) | 1.35 (1.26–1.45) |
| 3–11 | 1.71 (1.58–1.85) | 1.71 (1.58–1.85) | 1.59 (1.45–1.74) |
| 12+ | 2.42 (2.14–2.74) | 2.47 (2.18–2.80) | 2.32 (2.00–2.69) |
| P-trend | <.0001 | <.0001 | <.0001 |
| ≥14 drinks/week, 23–30 years old | |||
| Never | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| 1–2 | 1.15 (1.00–1.33) | 1.13 (0.98–1.31) | 1.08 (0.92–1.26) |
| 3–11 | 1.57 (1.32–1.86) | 1.50 (1.26–1.78) | 1.34 (1.10–1.62) |
| 12+ | 2.41 (1.89–3.08) | 2.21 (1.72–2.83) | 1.79 (1.35–2.38) |
| P-trend | <.0001 | <.0001 | <.0001 |
| ≥3 drinks/day | |||
| Never | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| 1–2 | 1.56 (1.49–1.63) | 1.52 (1.45–1.59) | 1.47 (1.40–1.55) |
| 3–11 | 1.75 (1.65–1.85) | 1.70 (1.60–1.80) | 1.62 (1.52–1.73) |
| 12+ | 2.09 (1.90–2.29) | 2.00 (1.81–2.20) | 1.82 (1.63–2.04) |
| P-trend | <.0001 | <.0001 | <.0001 |
| ≥6 cups coffee/day | |||
| Never | 1.00 (Ref) | 1.00 (Ref) | 1.00 (Ref) |
| 1–2 | 0.95 (0.81–1.12) | 0.97 (0.83–1.14) | 0.83 (0.70–0.98) |
| 3–11 | 1.19 (0.98–1.46) | 1.20 (0.98–1.47) | 1.08 (0.87–1.33) |
| 12+ | 2.22 (1.69–2.92) | 2.21 (1.68–2.90) | 1.50 (1.11–2.04) |
| P-trend | <.0001 | <.0001 | .03 |
CI, Confidence interval; OR, odds ratio; Ref, reference.
Past and current smoking status, alcohol consumption, and coffee intake measured at study baseline in 1989.
Adjusted for age (continuous, years), BMI (continuous, kg/m2), physical activity (continuous, metabolic equivalents/week), hair color (red, blonde, light brown, dark brown, black), number of severe sunburns between ages 15 and 20 years (none, 1–2, 3–4, 5–9, 10+), mole count on lower legs (none, 1–2, 3–9, 10+), family history of melanoma ( yes/no), and chronic disease at baseline ( yes/no).
Past and current smoking was further adjusted for alcohol consumption (≥14 drinks per week at ages 15–17, 18–22, and 23–30 years; yes/no), coffee intake (≥6 cups per day, yes/no), and food addiction (yes/no). Alcohol consumption was further adjusted for smoking status (never, past, current), coffee intake, and food addiction. Coffee intake was further adjusted for alcohol consumption, smoking status, and food addiction.