Demographic transition and hospital admissions in Spanish centenarians, 2004-2020: Geographical variations and sex-related differences.

Background: This study aims to describe the distribution and temporal trends of the centenarian population and their hospital admissions in Spain over the past two decades, focusing on regional and sex-based differences.

Methods: A retrospective study was conducted using data from the Spanish National Health System's Hospital Discharge Records-Minimum Basic Data Set. The analysis included all hospitalized patients ≥100 years between January 2004 and December 2020. The crude annual centenarian population and admission rates were calculated. Joinpoint regression analysis and cross-correlation analysis were used to identify trends and associations.

Results: From 2004 to 2020, the centenarian population in Spain increased by 89.0 %, with a larger increase observed in women (86.6 %) than men (32.9 %). Significant geographic variability was found, with rates from 1.1 to 5.2 × 10,000 inhabitants per year across different regions. Joinpoint analysis identified three trends: a decline from 2004 to 2008, an increase from 2008 to 2015, and a slower increase from 2015 to 2020. Hospital admissions of centenarians increased by 121.5 %, with a larger increase in women than men (212.1% vs 90.7 %); women represented 75.4 % of admissions. The proportion of centenarian admissions to total hospitalizations showed an upward trend until 2015 and then stabilized; it also varied among regions.

Conclusion: There was a significant increase in the centenarian population and hospital admissions of centenarians in Spain. There are regional disparities in their distribution, with women representing a larger proportion of centenarians and hospital admissions. Understanding these trends and differences is crucial for implementing interventions that ensure adequate healthcare for centenarians.