Association of Frailty With Risk of Incident Hospital-Treated Infections in Middle-Aged and Older Adults: A Large-Scale Prospective Cohort Study

Background Although frailty is associated with a range of adverse health outcomes, its association with the risk of hospital-treated infections is uncertain.Methods A total of 416 220 participants from the UK Biobank were included in this prospective cohort study. Fried phenotype was adopted to evaluate frailty, which included 5 aspects (gait speed, physical activity, grip strength, exhaustion, and weight). More than 800 infectious diseases were identified based on electronic health records. Cox proportional models were used to estimate the associations.Results During a median 12.3 years (interquartile range 11.4-13.2) of follow-up (4 747 345 person-years), there occurred 77 988 (18.7%) hospital-treated infections cases. In the fully adjusted model, compared with participants with nonfrail, the hazard ratios (HRs) (95% confidence intervals [CIs]) of those with prefrail and frail for overall hospital-treated infections were 1.22 (1.20, 1.24) and 1.78 (1.72-1.84), respectively. The attributable risk proportion of prefrail and frail were 18.03% and 43.82%. Similarly, compared to those without frailty, the HRs (95% CIs) of those with frailty for bacterial infections were 1.76 (1.70-1.83), for viral infections were 1.62 (1.44-1.82), and for fungal infections were 1.75 (1.47-2.08). No association was found between frailty and parasitic infections (HR: 1.17; 95% CI: 0.62-2.20).Conclusions Frailty was significantly associated with a higher risk of hospital-treated infections, except for parasitic infections. Studies evaluating the effectiveness of implementing frailty assessments are needed to confirm our results.