Table 3.

Association between nevi on the back at 12 years of age and average sun protection measures during the previous summer and the summer 2.5 years before

n (total = 921)Ratio (95% confidence interval)*PAdjusted mean
Time spent outdoors between 11 a.m. and 2 p.m.
    Actual time9171.09 (1.05-1.12)<0.001
    Proportion of total,§9071.10 (1.05-1.14)<0.001
Percentage of time back covered with clothing
    <70%224 (24%)1.53 (1.34-1.75)<0.00112.0
    70-84%204 (22%)1.34 (1.17-1.53)10.5
    85-99%288 (31%)1.29 (1.14-1.45)10.1
    100%205 (22%)1.007.9
  • * Ratio of geometric means. Adjusted for sex, southern European ethnicity, parental education, propensity to burn, hair color, inner arm skin reflectance, and study group. Time spent outdoors and back cover were adjusted for each other.

  • Adjusted geometric mean of “nevi + 1,” with values of covariates set to the distribution of the subjects included in the analysis.

  • Estimate corresponds to a doubling of the time outdoors.

  • § Proportion of the total time spent outdoors between 8 a.m. and 5 p.m.

  • P for trend.