Sex-stratified multimorbidity trajectories in UK Biobank cohort identify triage rules for the risk of mortality and hospitalisation in secondary care

Clinical presentation of diseases is complicated by multimorbidity. There is a pressing need to understand the effects of multimorbidity and where interventions should be targeted. We performed a data-driven analysis of whole-cohort UK Biobank hospital inpatient data in women and men and assembled ICD10 disease sequence trajectories. Age-relative 1-year mortality and hospitalisation rates were calculated post-trajectory using Accelerated Failure Time models with a 1:3 case-control ratio. We show that prior disease trajectories can stratify 1-year post-diagnosis mortality and hospitalisation outcomes for 63 common diseases in secondary care and highlight the impact of prior disease trajectories on mortality outcomes for respiratory failure, renal failure, nerve disorders, hypotension, influenza/pneumonia, and sepsis. Mortality and hospitalisation rates varied from 1.05 to 17594.44 and 2.85 to 582.99 times faster than age-matched controls, respectively. From this, we create triage rules that identify the highest risk multimorbid patients and highlight where intervention can have the greatest impact.