Age as a Poor Proxy for Frailty Complexity: A Comparative Analysis of 2023 and 2025 Frailty Census Data

Introduction
Frailty represents a multidimensional vulnerability associated with adverse outcomes in hospital and community settings. Despite this complexity, chronological age is often used as a surrogate marker for frailty severity. This study evaluates whether age reliably reflects frailty complexity by analysing two frailty census datasets collected in 2023 and 2025.

Method
Two frailty data sets at PPH (June 2023 and December 2025) were examined. Key variables extracted included age and Clinical Frailty Score (CFS). Data were cleaned and converted to numeric formats. Only rows with valid values for both age and CFS were included in the analysis (2023: n=72; 2025: n=168). Pearson’s correlation coefficient was used to assess the association between age and frailty severity.

Results
In the 2023 dataset (n=72), the correlation between age and CFS was r = 0.197, indicating a very weak association. Similarly, in the 2025 dataset (n=168), the correlation between age and CFS was r = 0.190. Across both datasets, individuals of similar ages displayed a wide range of frailty levels: adults in their 60s and early 70s appeared across all CFS categories, including high frailty (CFS ≥ 6), while many adults aged ≥ 85 had low or moderate frailty scores. Overall, only approximately 4% of the variance in frailty severity was explained by age (r² ≈ 0.04), demonstrating minimal predictive value.

Conclusions
Across two independent datasets collected two years apart, chronological age shows only a weak relationship with frailty severity. These findings support the conclusion that age is a poor proxy for frailty complexity, and that reliance on age alone risks misclassification and misallocation of healthcare resources. More comprehensive frailty assessment tools—particularly the Clinical Frailty Score—provide more accurate and clinically meaningful evaluation and should be prioritised over age-based assumptions