Acute clinical events and trajectories of frailty after age 60: A population-based cohort study

Background: We aimed to examine the relationship between acute events and frailty trajectories of community-dwelling adults aged 60 and older. Methods: We included 3146 participants, aged 60+, from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K). We considered all myocardial infarctions (MIs), lower respiratory tract infections (LRTIs) and falls that resulted in a hospitalization 5 years before to 12 years after SNAC-K baseline (2001–2004). Frailty was operationalized using a data-driven frailty index (FI), scored from 0 to 1. Linear quantile mixed models were used to examine the relationship between number and type of acute events and FI trajectories over a median follow-up of 11 years. Results: Falls (n = 690) were most common, followed by LRTIs (n = 353) and MIs (n = 205). Those with more acute events showed significantly higher frailty levels over time from age 75 to 95. The greatest differences in frailty trajectories by event count were observed at age 80, with increases between zero to one, one to two and two to three or more events of 0.04 (95% confidence interval [CI] = 0.03–0.05), 0.08 (95% CI = 0.05–0.11) and 0.09 (95% CI = 0.05–0.13) FI units, respectively. Falls emerged as most deleterious, but there were also clear differences by MI and LRTI count after imputing frailty at death. Conclusion: Older adults who experience falls, LRTIs and MIs are more likely to sustain unfavourable frailty trajectories, with increasingly higher frailty levels with each additional acute event. Prevention, before age 75, should be optimized to avoid a vicious cycle of acute events and frailty progression as well as reduced lifespan.