Age period and no. of bathing vacations | No. of cases | Age-adjusted | Multivariate^{*} |
---|---|---|---|

RR (95% CI) | RR (95% CI) | ||

<10 y (n = 46,287) | |||

0 | 71 | 1.00 | 1.00 |

≥1 wk/y | 24 | 1.14 (0.72-1.82) | 1.12 (0.70-1.79) |

P = 0.57 | P = 0.65 | ||

10-19 y (n = 90,450) | |||

0 | 73 | 1.00 | 1.00 |

1 wk/y | 16 | 0.58 (0.34-1.00) | 0.67 (0.38-1.16) |

≥2-3 wk/y | 44 | 1.14 (0.78-1.66) | 1.24 (0.84-1.82) |

P_{trend} = 0.69 | P_{trend} = 0.38 | ||

20-29 y (n = 92,946) | |||

0 | 41 | 1.00 | 1.00 |

1 wk/y | 43 | 1.09 (0.71-1.68) | 1.19 (0.77-1.84) |

≥2-3 wk/y | 61 | 1.12 (0.75-1.66) | 1.16 (0.77-1.73) |

P_{trend} = 0.59 | P_{trend} = 0.51 | ||

30-39 y (n = 90,806) | |||

0 | 34 | 1.00 | 1.00 |

1 wk/y | 41 | 1.04 (0.66-1.64) | 1.06 (0.67-1.68) |

≥2-3 wk/y | 68 | 1.21 (0.80-1.82) | 1.17 (0.77-1.77) |

P_{trend} = 0.34 | P_{trend} = 0.45 | ||

40-49 y (n = 43,459) | |||

0 | 24 | 1.00 | 1.00 |

1 wk/y | 24 | 1.05 (0.60-1.85) | 1.10 (0.62-1.94) |

≥2-3 wk/y | 42 | 1.25 (0.76-2.07) | 1.26 (0.76-2.11) |

P_{trend} = 0.36 | P_{trend} = 0.36 | ||

Combined, 10-39 y (n = 85,667) | |||

0, 10-39 y | 26 | 1.00 | 1.00 |

≥1/y, 10-39 years | 105 | 0.96 (0.63-1.48) | 1.00 (0.64-1.54) |

P = 0.87 | P = 0.98 |

NOTE: Poisson regression analysis. All statistical tests were two-sided. Bathing vacations at age <10 years were only recorded for the Norwegian women. Analyses of bathing vacations at ages 40 to 49 years included only women ≥40 years when answering the questionnaire.

↵*Multivariable models included attained age, region of residence, hair color, eye color and skin color after heavy sun exposure in the beginning of the summer and after repeated sun exposure.