Abstract
OBJECTIVES: To investigate the rate and patterns of accumulation of frailty manifestations in relationship to all-cause mortality and whether there is a point in the progression of frailty beyond which the process becomes irreversible and death becomes imminent (a.k.a. point of no return). DESIGN: Longitudinal observational study. SETTING: Community or a non-nursing home residential care setting. PARTICIPANTS: Two thousand five hundred and fifty seven robust older adults identified at baseline in 2011 with follow-up for all-cause mortality between 2011 and 2018. MEASUREMENTS: Frailty was measured by the physical frailty phenotype. Cox models were used to study the relationships of the number of frailty criteria (0-5) at each point in time and its accumulation patterns with all-cause mortality. Markov state-transition models were used to study annual transitions between health states (i.e., frailty, recovery, and death) after becoming frail among those with frailty onset (n = 373). RESULTS: There was a nonlinear association between greater number of frailty criteria and increasing risk of mortality, with a notable risk acceleration after having accumulated all five criteria (hazard ratio (HR) = 32.6 vs none, 95% confidence interval (CI) = 15.7-67.5). In addition, the risk of one-year mortality tripled, and the likelihood of recovery (i.e., reverting to be robust or pre-frail) halved among those with five frailty criteria compared to those with three or four criteria. A 50% increase in mortality risk was also associated with frailty onset without (vs with) a prior history of pre-frailty (HR = 1.51, 95% CI = 1.20-1.90). CONCLUSION: Both the number and rate of accumulation of frailty criteria were associated with mortality risk. Although there was insufficient evidence to declare a point of no return, having all five-frailty criteria signals the beginning of a transition toward a point of no return. Ongoing monitoring of frailty progression could aid clinical and personal decision-making regarding timing of intervention and eventual transition from curative to palliative care.