Estimating the number of centenarians and the oldest-old in Thailand : trends in old age longevity from 1960 to 2010

• Main Author: Sutthida Chuanwan
• Other Authors: Pramote Prasartkul
• Language: English
• Published: Mahidol University. Mahidol University Library and Knowledge Center 2023
• Subjects: Older people; Aging; Centenerians > Thailand; Longevity > Thailand; Survival Rate
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/89428
• Institution: Mahidol University

The objectives of this study were to estimate the number of centenarians and the quality of centenarian data in civil registration in Thailand. Data from several sources, namely the series of population census, the Survey of Population Change (SPC), the Coale and Demeny regional model life tables, and United Nations World Population Prospects (UN WPP) were used. The data from censuses were employed to calculate survival ratios among the oldest old. These survival ratios were then applied to appropriate model life tables. The data on centenarians as reported in the civil registration from two sample provinces were collected to support and qualitatively explain the prior quantitative findings. These demographic procedures yielded an estimate of about 1,700 surviving centenarians in 2010, which was only 12% of the number recorded in official civil registration figures. The inflated estimates of the centenarian population recorded by the civil registration system were investigated by in-depth interviews of centenarians, village/sub-district headmen, registrars, and relatives of deceased persons in the two selected provinces. Names and addresses of centenarians were acquired from civil registration and were followed up to evaluate their accuracy. Among 429 recorded centenarians, only 43 cases (10%) were found to be true centenarians. Among the remaining 90% of recorded centenarians, most had already died and some were found to have ages of less than 100 years. The ages of all recorded centenarians over 106 years were found to be incorrectly recorded and were over reported in all cases. It was also found that incompleteness of death registration and incorrect age recording were the main causes of the inflated figures of centenarians found in registration data in Thailand.