Association between indoor tanning and risk of melanoma by possible recall and selection bias among cases and controls (Skin Health Study)
| Observed | Cases | Controls | Crude OR (95% CI) | Adjusted OR (95% CI)* |
|---|---|---|---|---|
| All participants | ||||
| n | 1,167 | 1,101 | ||
| % 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 physician† | ||||
| n | 21 | 3 | ||
| % ever tanned indoors | 71.4 | 66.7 | 1.25 (0.10-16.50) | —‡ |
| 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 | ||||
| Nonparticipants who answered brief questionnaire | ||||
| n | 107 | 180 | ||
| % ever tanned indoors | 60.8 | 48.3 | 1.62 (1.00-3.61) | —§ |
↵*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, and number of lifetime painful sunburns; analysis among all participants excludes an additional 16 cases and 12 controls because the number of missing values was too small to be included as its own category. Analysis of recall bias excludes only two additional cases and three controls for the same reason.
↵†Excludes nine cases and three controls who responded “don't know” or whose response was missing.
↵‡Not possible to estimate due to small numbers.
↵§Confounders not collected on nonparticipants.
↵*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, and number of lifetime painful sunburns; analysis among all participants excludes an additional 16 cases and 12 controls because the number of missing values was too small to be included as its own category. Analysis of recall bias excludes only two additional cases and three controls for the same reason.
↵†Excludes nine cases and three controls who responded “don't know” or whose response was missing.
↵‡Not possible to estimate due to small numbers.
↵§Confounders not collected on nonparticipants.