Beyond One Hundred: A Cohort Analysis of Italian Centenarians and Semisupercentenarians

Abstract

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.

Cohort analysis of gender gap after one hundred years old: the role of differential migration and survival trajectories

“…We can obviously have the survivors of the life tables at every age from 100 to ω. In the last step we have linked this end-of table to the table computed using the classic method for the previous ages, in this way we have the whole survival trajectories of the cohorts considered [4].…”

“…Only 4.0% and 12.0%, respectively, of the initial 60-year olds reached the age of 90, against, as we have seen, 6.4% and 25.9% for women. The number of men reaching 100 is very limited: 0.05% of the 60-year olds of cohort 1870, and little more than 0.8% for that of 1912 [4]. It is interesting to consider the left-hand side of Figure 6 and refer to the lines of differences with the cohorts with higher values than those indicated in bold for the last cohort of 1912.…”

“…Age validation is still the most important prerequisite for any study of this population [2,3]. Its absence is likely to bias the calculation of centenarian or semi-supercentenarian rates, the differences in gender gap at these ages and, consequently, any explanation of this extreme differential longevity [4].…”

“…The persistence of mortality decline at all ages, and particularly at older ages, means that an increasing number of individuals are becoming centenarians and semi-supercentenarians too [4]. Women are more likely to cross these thresholds, and to such an extent that in low-mortality countries there are 5 to 7 women per man beyond the age of 100 years.…”

“…The Italian National Institute of Statistics (Istat) has been involved in collecting the data on semi super and supercentenarians (110 and over) since 2009, when the IDL protocol set up the SSC survey to specifically investigate this question. This survey has collected data about living and dead individuals aged 105 and over for the cohorts born between 1896 and 1912 by their birth and place of residence [4,11]. We have made use of this information, together with that on deaths from 100 to 105 years, collected in other Istat surveys, and on life tables available for dead cohorts born after 1870 and now extinct.…”