Beyond One Hundred: A Cohort Analysis of Italian Centenarians and Semi-supercentenarians.

Although the increase in the number of centenarians is well documented today in countries with advanced demographic data, the same is not true for those aged 105 and over. The first aim of this paper, was to analyze the demographic characteristics of the 4,626 validated semi-super and 102 supercentenarians for the cohorts born between 1896 and 1910, referring to Italian Semi-Supercentenarians Survey (SSC). Then, starting from this data and from the survival  histories  in old ages - reconstructed by Vincent's Extinct - Cohort Method - for the cohorts born between 1870 and 1904, the most important aim was to analyze longevity history and the trend of gender gap of the Italian oldest cohorts beyond 100 years old.  The Italian centenarians and semi-supercentenarians increase from the first to the last cohort is due to the survival rise in old ages and the increase in the gender gap at extreme ages depends on the higher survival of women than men after 60 years old. Around 110-112 for both genders (for women in particular) a kind of resistance to further progress seems to appear in our analysis as in more recent studies on supercentenarians.