Table 5. Association between indoor tanning and risk of melanoma by possible recall and selection bias among cases and controls, Skin Health Study.
| Cases | Controls | Crude Odds Ratio 95% CI | Adjusted Odds ratio† 95% CI | |||
|---|---|---|---|---|---|---|
| Observed | ||||||
| All Participants | ||||||
| N | 1167 | 1101 | ||||
| % ever tanned indoors | 62.9 | 51.1 | 1.62 | (1.37, 1.92) | 1.74 | (1.42, 2.14) |
| Evaluation of recall bias | ||||||
| Participants who talked with their physician1 | ||||||
| N | 21 | 3 | ||||
| % ever tanned indoors | 71.4 | 66.7 | 1.25 | (0.10, 16.50) | --2 | |
| Participants who did not talk with their physician | ||||||
| N | 130 | 188 | ||||
| % ever tanned indoors | 57.7 | 52.7 | 1.23 | (0.78, 1.92) | 1.72 | (0.92, 3.22) |
| Evaluation of selection bias | ||||||
| Non-participants who answered brief questionnaire | ||||||
| N | 107 | 180 | ||||
| % ever tanned indoors | 60.8 | 48.3 | 1.62 | (1.00, 3.61) | --3 | |
1
Excludes 9 cases and 3 controls who responded “don't know” or whose response was missing.
2
Not possible to estimate due to small numbers.
3
Confounders not collected on non-participants.
†
Adjusted for age, gender, eye color, natural hair color, skin color, freckles, moles, income, education, family history of melanoma, routine sun exposure, outdoor activity sun exposure, outdoor job exposure, mean sunscreen use, number of lifetime painful sunburns; analysis among all participants excludes additional 16 cases and 12 controls because the number of missing was too small to be included as its own category; analysis of recall bias excludes additional 2 cases and 3 controls only for the same reason.