From: Calculating incidence rates and prevalence proportions: not as simple as it seems

Numerator | Denominator | |
---|---|---|

Incidence rate | ||

Incidence rate: person-years | Sum of all new episodes of illness in 2012 | Person-years |

Incidence rate: person-years at-risk | Sum of all new episodes of illness in 2012 | Person-years at-risk |

Incidence rate: midterm population | Sum of all new episodes of illness in 2012 | Midterm population |

Prevalence proportion | ||

Point-prevalence proportion | Episodes on December 31th | Population on December 31th |

1 year period prevalence proportion | Episodes in 2012 | Person-years |

Contact prevalence proportion | Number of persons with ≥1 contact in 2012 | Person-years |