Postoperative outcomes in older patients living with frailty and multimorbidity in the UK: SNAP-3, a snapshot observational study

Older surgical patients experience longer hospital stays and a higher risk of morbidity and mortality than their younger counterparts. Frailty (19.6% of cohort) and multimorbidity (63.1% of cohort) increase these risks. The 3rd Sprint National Anaesthesia Project (SNAP-3) describes the impact of frailty and multimorbidity on postoperative outcomes. We conducted a prospective observational cohort study over 5 days in 2022 aiming to recruit all UK patients aged ≥60 yr undergoing surgery (excluding minor procedures). Data included patient characteristics, clinical variables, Clinical Frailty Scale (CFS), multimorbidity (two or more comorbidities), length of stay (LOS), postoperative delirium, morbidity, and mortality. Quantile regression and mixed effects logistic regression were used to analyse relationships. We recruited 7129 patients from 214 hospitals. Increasing frailty was associated with longer LOS, higher odds of delirium, morbidity, and mortality ≥1 yr, with a clear increase noted from CFS of 4 (19.0% of cohort). Amongst those without multimorbidity, individuals with CFS score of 4 had longer admissions than non-frail individuals (median LOS 0.75 days longer, 95% confidence interval [CI] 0.34-1.16), increasing to 2.69 days longer for CFS 5 (95% CI 0.76-4.62). Multimorbidity increased the odds of postoperative morbidity by 46% (adjusted odds ratio 1.46, 95% CI 1.24-1.73), but there was no evidence for multimorbidity impacting LOS, delirium, or mortality. SNAP-3 highlights the impact of frailty on postoperative outcomes. Multimorbidity had less impact, with an effect on postoperative morbidity the only one to have strong statistical evidence. The impact of these conditions must be discussed with older patients considering surgical intervention.