Table 3.
Univariate Analyses of Back Freckling, Sun-Exposure Variables, and Log Total Nevus Count, Adjusted for the Linear and Quadratic Effect of Sun Sensitivity Index, in a Study of Nevi in Children, Framingham, Massachusetts, 2004
| Variable and Response Category | Sample Size | Rate Ratio | 95% CI | P value |
| On a typical day during the week this past summer between 10 AM and 4 PM, how many hours did you spend at the beach or pool? | ||||
| <1 (baseline) | 69 | 1.0 | ||
| 1–2 | 168 | 1.17 | 0.97, 1.42 | 0.109 |
| 3–4 | 152 | 1.16 | 0.89, 1.51 | 0.283 |
| 5–6 | 54 | 1.10 | 0.84, 1.43 | 0.480 |
| 0.46a | ||||
| On a typical day during the week this past summer between 10 AM and 4 PM, how many hours did you spend outdoors? | ||||
| <1 and 1–2 (baseline) | 131 | 1.0 | ||
| 3–4 | 166 | 1.05 | 0.87, 1.25 | 0.632 |
| 5–6 | 146 | 1.27 | 1.05, 1.53 | 0.014 |
| 0.03a | ||||
| On a typical day during the weekend this past summer between 10 AM and 4 PM, how many hours did you spend at the beach or pool? | ||||
| <1 (baseline) | 54 | 1.0 | ||
| 1–2 | 143 | 1.29 | 1.04, 1.58 | 0.018 |
| 3–4 | 172 | 1.22 | 1.00, 1.49 | 0.053 |
| 5–6 | 74 | 1.26 | 1.08, 1.47 | 0.004 |
| 0.02a | ||||
| On a typical day during the weekend this past summer between 10 AM and 4 PM, how many hours did you spend outdoors? | ||||
| <1 and 1–2 (baseline) | 142 | 1.0 | ||
| 3–4 | 183 | 1.15 | 0.92, 1.44 | 0.219 |
| 5–6 | 118 | 1.33 | 1.05, 1.67 | 0.016 |
| 0.03a | ||||
| During the past summer, did you spend time in the sun to get a tan? | ||||
| No (baseline) | 342 | 1.0 | ||
| Yes | 101 | 1.16 | 0.93, 1.45 | 0.178 |
| Did you get a tan on any part of your skin this summer? | ||||
| No (baseline) | 67 | 1.0 | ||
| Yes | 376 | 1.15 | 0.95, 1.40 | 0.151 |
| Did you get a tan on your back this summer? | ||||
| No (baseline) | 108 | 1.0 | ||
| Yes | 335 | 1.14 | 0.98, 1.33 | 0.088 |
| Do you like to get a suntan? | ||||
| No (baseline) | 210 | 1.0 | ||
| Yes | 233 | 1.04 | 0.88, 1.22 | 0.642 |
| How many times did your skin stay red or pink for 12 or more hours, after being out in the sun this past summer? | ||||
| None (baseline) | 221 | 1.0 | ||
| 1 | 99 | 1.28 | 1.01, 1.62 | 0.044 |
| 2 | 70 | 1.22 | 0.90, 1.67 | 0.202 |
| 3–4 and ≥5 | 53 | 1.23 | 0.96, 1.58 | 0.102 |
| 0.13a | ||||
| How many times did you get a painful sunburn this past summer? | ||||
| None (baseline) | 286 | 1.0 | ||
| 1 | 110 | 1.33 | 1.01, 1.76 | 0.043 |
| 2 and 3–4 and ≥5 | 47 | 1.49 | 1.11, 2.01 | 0.009 |
| 0.005a | ||||
| How many times did your back stay red or pink for 12 or more hours, after being out in the sun this past summer? | ||||
| None (baseline) | 273 | 1.0 | ||
| 1 | 107 | 1.24 | 1.03, 1.49 | 0.024 |
| 2 and 3–4 and ≥5 | 63 | 1.22 | 0.98, 1.52 | 0.071 |
| 0.03a | ||||
| How many times did you get a painful sunburn on your back this past summer? | ||||
| None (baseline) | 322 | 1.0 | ||
| 1 | 87 | 1.21 | 0.90, 1.63 | 0.204 |
| 2 and 3–4 and ≥5 | 34 | 1.32 | 0.94, 1.85 | 0.113 |
| 0.08a |
Abbreviation: CI, confidence interval.
a
Trend-test P value.