Table 3.
Effect of mutual adjustment of age at first use of sunbeds and number of lifetime sessions on ORs for melanoma, in participants who reported ever using a sunbed
| OR & 95% CIa |
||||
|---|---|---|---|---|
| Adjusted for lifetime sunbed sessionsb? | ||||
| Age at first use of sunbeds | Casesc | Controlsc | No | Yes |
| ≥ 25 years | 46 | 39 | 1.00 | 1.00 |
| < 25 years | 81 | 41 | 1.32 (0.70-2.48) | 1.18 (0.62-2.25) |
| P diff | 0.39 | 0.61 | ||
| ≥ 25 | 46 | 39 | 1.00 | 1.00 |
| 20-24 | 45 | 26 | 1.14 (0.55-2.35) | 1.07 (0.51-2.22) |
| < 20 | 36 | 15 | 1.63 (0.72-3.70) | 1.39 (0.59-3.23) |
| P trend | 0.26 | 0.48 | ||
| Adjusted for age at first useb? | ||||
|---|---|---|---|---|
| Lifetime sunbed sessions | Cases | Controls | No | Yes |
| 1-10 | 67 | 55 | 1.00 | 1.00 |
| >10 | 60 | 25 | 2.07 (1.08-4.00) | 2.01 (1.04-3.89) |
| P diff | 0.03 | 0.04 | ||
a
All models were adjusted for age, sex, city of recruitment, education, family history of melanoma, skin colour, usual skin response to sun exposure, and cumulative lifetime total sun exposure.
b
Adjustment for number of lifetime sunbed sessions as a continuous variable and age at first use in categories (<20, 20-24, ≥ 25).
c
Excludes cases and controls who had never used a sunbed (467 cases, 395 controls), or who had missing data for number of lifetime sessions or age at first use (8 cases, 4 controls).