Maximum Normal Longevity in Low Mortality Countries

Siu Lan Karen Cheung, Università di Roma "La Sapienza"
Jean-Marie Robine, Institut National de la Santé et de la Recherche Médicale (INSERM)

Kannisto (2001) proposed to look at the late mode (M) and standard deviation above it (SD(M+)) for examining normal human longevity. With data from 15 low mortality countries, he showed that the later M occurs, the smaller SD(M+) is. This observation leads him to wonder if increase in longevity is meeting an invisible wall. A recent study using Hong Kong data confirms this negative relationship between M and SD(M+) from 1976 to 2001. Moreover, using four standard deviation above the mode (M + 4SD(M+)) as indicator of the longest normal life durations, the study shows that the reduction in 4SD(M+) compensates for the rise in M resulting in an almost constant longest normal life duration for the last 25 years. This paper aims to examine whether the value of about 120 years found in Hong Kong for the longest normal life durations, is confirmed in other low mortality countries.