Abstract
Frailty is an important age-associated risk-state. Despite this, many countries lack population estimates and large heterogeneity exists amongst studies. The Global Burden of Disease (GBD) study, provides comparable high-quality population-level data for 195 countries and territories. Frailty has never been measured in the GBD studies. This analysis applies the deficit accumulation model to construct a novel frailty index (FI) using the GBD 2017 dataset. Standard FI criteria were applied to all GBD categories such that selected items were health-related, age-correlated, sufficiently prevalent, did not saturate at an early age, had little redundancy/duplication, covered a range of systems, were plausible and were available serially for the same population. From all 554 GBD items, 36 were selected including 26 non-communicable diseases, 3 metabolic risks, 3 biological impairments, infectious diarrheal diseases, protein-energy malnutrition, injurious falls, and low physical activity. Variable face validity was displayed against a selection of established FIs. The mean GBD-FI score for the global population aged ≥70 years in 2017 was 0.16; scores were higher in females than males (0.16 vs 0.15, respectively). Deficits accumulated with age at an estimated rate of 0.026 per year. Adding the mean GBD-FI scores to a regression model including country-level variables for demographics (proportion ≥85 years, proportion female), healthcare quality (HAQ index), and development (SDI) increased the adjusted r2 value from 27.0% to 39.6% (p<0.001) for predicting country-level death rates from non-communicable diseases, suggesting that the GBD-FI is a useful predictor of mortality. Further analysis is required to compare the reliability and predictive validity of the GBD-FI with existing frailty tools