Evidence | Criteria used | Decreased risk | |

Any physical activity | Recreational physical activity | ||

Strong | *P<10^{−6}; >1000 cases; P<0.05 of the largest study in a meta-analysis; I^{2}<50%; no small study effect†; prediction interval excludes the null value; no excess significance bias‡ | None | Colon cancer, inc. or mort. |

Highly suggestive | *P<10^{−6}; >1000 cases; P<0.05 of the largest study in a meta-analysis | Breast cancer, inc. and all cancer, mort. | None |

Suggestive | *P<10^{−3}; >1000 cases | Colon cancer, inc. or mort, lung inc. and endometrial, inc. | All cancer, mort. and lung, inc. |

Weak | *P<0.05 | Meningioma, inc. or mort, multiple cancer sites, inc. or mort, pancreas, inc. | Oesophageal, inc. and meningioma, inc. or mort. |

*P indicates the P values of the meta-analysis random effects model.

†Small study effect is based on the P value from the Egger’s regression asymmetry test (P≤0.1) where the random effects summary estimate was larger compared with the point estimate of the largest study (smallest SE) in a meta-analysis.

‡Based on the P value (P>0.1) of the excess significance test using the largest study (smallest SE) in a meta-analysis as the plausible effect size.

inc., incidence; mort., mortality.