Distinctness of all-cause mortality attributable to physical frailty among Brazilian men and women: 5-year follow-up of the ELSI-Brazil study

Abstract

Background: Sex differences and increased mortality patterns attributable to frailty has been overlooked in upper-middle-income countries. This study aims to examine the impact of physical frailty on all-cause mortality among adults according to sex, in a Western upper-middle-income country.

Methods: This longitudinal analysis utilized data from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a nationally representative sample of adults aged 50 years and over (N = 7121), linked with the official Brazilian database. Follow-up period was from May 2015 to March 2021 (average 5-year follow-up). All-cause of death was based on participants' death certificates at the time of the ELSI-Brazil wave 2 or via inclusion in the official Brazilian database. Physical Frailty was defined by unintentional weight loss, exhaustion, low physical activity, slow gait and weakness. Statistical analyses were conducted using Cox proportional hazards regression models and population attributable fraction (PAF).

Results: During the study period, 685 participants have died. Frailty significantly increased the risk of death in both women (HR=4.15; 95 %CI 2.64-6.52) and men (HR=2.93; 95 %CI 1.90-4.49), with similar PAF of 37.3 % (95 %CI 31.4-42.7) and 33.5 % (95 %CI 25.4-40.7), respectively. However, pre-frailty increased the risk of death only in women (HR=1.58; 95 %CI 1.06-2.36), resulting in a PAF of 25.2 % (95 %CI 5.34-40.9).

Conclusion: Our findings highlight sex differences in the prediction of physical frailty on all-cause mortality in an upper-middle-income country. Public policies should adopt a differentiated approach by sex to address early mortality risks targeting pre-frailty. Tailoring interventions based on sex-specific vulnerabilities may help mitigate the increased mortality risk in older adults.

Keywords: Frailty; Gender Equity; Gender and health; Mortality.