Population frailty trends by education and income levels over a period of 30 years: findings from Swedish registry data.

Background: Frailty is an age-related health condition affecting an estimated 18% of older adults in Europe and past evidence has shown a relationship between socioeconomic factors and frailty. We examined population frailty trends and the association between frailty and 5-year mortality by education tertiles and income quartiles at ages 75, 85 and 95 in Swedish registry data.

Methods: All Swedish residents born in 1895-1945 and in the Total Population Register from 1990 to 2020 were included. Frailty was assessed with the Hospital Frailty Risk Score (HFRS), which sums 109 weighted International Classification of Diseases (ICD codes), collected from the National Patient Register.

Results: Regardless of education and income, frailty increased over time, though the association between frailty and 5-year mortality remained stable. Particularly in earlier birth cohorts, although the highest education and income levels had the highest mean HFRS scores, the lowest education and income levels accounted for greater proportions among the frail. These trends varied slightly by sex and age. Men and women had similar levels of frailty, but frailty was more strongly associated with mortality among men.

Conclusion: Over time, education and income levels were more equally represented among the frail population in more recent years. More equitable distribution over time may suggest improvement in health disparities, though more work is needed. The overall increase in frailty and unchanged association with mortality indicates that additional research is needed to better understand how to best support the growing ageing population. This would then support the long-term viability of the healthcare system.