Social factors associated with centenarian rate (CR) in 32 OECD countries

BACKGROUND Over the last fifty years, the number of centenarians has dramatically increased. The centenarian rate (CR) is representative of the general longevity prevalent in a nation; it indicates the number of individuals aged 100 years or above at a given date divided by the size of the corresponding cohort of a given age. Two important attributes of the CR (50-54) are that it reflects both unchanged age-specific fertility and the absence of migration in populations. It can generally be used in longevity-based evaluations of the broader concept of successful ageing. As such, this retrospective analysis of the social factors that contribute to the CR (50-54) may help to identify the factors associated with successful ageing.This study estimates the CR (50-54) and elucidates the influence of social factors on successful ageing and the CR (50-54), examining 32 member countries of the Organization for Economic Co-operation and Development (OECD). METHODS The social indicators for this study were obtained from the United Nations database. The data for the analysis of centenarians in the 32 OECD countries were obtained from the world population prospects conducted by the United Nations. Associations between social factors and CR (50-54) were assessed using Pearson correlation coefficients and regression models. RESULTS Significant positive correlations were found between the CR (50-54) and the social factors of expenditure on health as a percentage of gross domestic product (HEGDP: r = 0.411, p < 0.021), general government expenditure on health as a percentage of total government expenditure (GGEH: r = 0.474, p < 0.006), the proportion of fixed-telephone subscriptions in the population (FTS: r = 0.489, p < 0.005), and the human development index (HDI: r = 0.486, p < 0.005). Finally, these CR (50-54) predictors were used to form a model of successful ageing, with higher HEGDP and GGEH as health expenditure, higher FTS as standard of living, and higher HDI as social well-being (R2 = 0.573, P < 0.025). CONCLUSIONS The findings suggest that an increased CR (50-54) is affected by multiple social factors involved in successful ageing. Therefore, if they wish to improve their country's CR (50-54), governments must strengthen their existing support services for the elderly through making improvements to standards of living, social well-being and through increased financing of the health sector.