1. Data on the mortality of the oldest-old
The compilation of the data which have been used for the present report and, it is hoped, will be used for many studies to follow, began as a hobby in statistical libraries in Lisbon, Helsinki and Geneva, originally to satisfy the curiosity as to what is happening at the top of the age pyramid. It soon became clear that for a comprehensive view direct assistance of national statistical offices was necessary. In international conferences and by correspondence the author therefore contacted, beginning in 1987, responsible officials of 48 countries most likely to have data on deaths at old age, sufficiently reliable and detailed for application of the method of extinct generations of Paul Vincent which from the beginning was considered to be the method of choice for the purpose.
Positive response was received from 42 countries and ultimately material from 30 among them were found suitable for due and uniform treatment and were arranged into cohort mortality histories. A.R. Thatcher had undertaken to do the same for England and Wales and so contributed this indispensable element to the international picture. Following an offer by James W. Vaupel, the data for all 31 countries were computerized at the University of Odense to form the Kannisto - Thatcher Oldest-Old Database within the Odense Archive of Population Data on Aging.
The intention has been to assemble mortality statistics on old persons from all countries which process them by sex and single years of age, preferably combined with the year of birth and without any upper limit or at least up to age 99. The sources include official publications as well as unpublished materials made available by national statistical agencies, in some cases specially tabulated at request.
The stored data begin at age 80 and start for most countries with the year 1950. Some series, however, begin at a later date while some others reach back to last century. The latest year on record varies by country but is at this time in most cases 1990 or 1991.
The geographic coverage of countries fulfilling the data requirements is nearly complete but efforts will continue to expand it and to encourage more countries to produce comparable data. The contents of the database as of this writing are summed up in Table 1.
Updated by V. Castanova, 1 March 1999