Prevalence and outcomes of physical frailty by cognitive status in older people with emergency hospitalisation in ORCHARD-EPR

Background: Over one-third of older people with unplanned admissions to hospital have physical frailty, but there are few data on prevalence and outcomes by cognitive status necessary to individualise care.

Methods: ORCHARD-EPR includes consecutive patients ≥70 years with length of stay (LoS) of ≥1 day (2017–2019) admitted to four Oxfordshire, UK hospitals. Physical frailty was determined using a modified Hospital Frailty Risk Score excluding dementia and delirium (mHFRS). Cognitive frailty was defined using a mandatory on-admission cognitive screen as one or more of 10-point Abbreviated Mental Test score (AMT)<8, dementia and/or delirium diagnosis informed by the Confusion Assessment Method-CAM. Hazard/odds ratios adjusted for age, sex, comorbidity and illness severity were determined for survival, LoS, readmissions for no vs any cognitive frailty.

Results: Among 28,590 patients (mean/SD age=81.8/7.4 years, 52% female), 9,137 were cognitively frail, including 6,197 with delirium. Most patients with cognitive frailty had moderate/severe physical frailty (mHFRS≥5; 73%; 6,677/9,137), but fewer than half with moderate/severe physical frailty had cognitive frailty (46%; 6,677/14,544). Physical frailty had limited effects on mortality in cognitively frail patients (moderate frailty: adjHR=1.11 [95%CI 1.04-1.19], p<0.001; severe frailty: 1.01 [0.92-1.11], p=0.82) but was more strongly predictive of survival in the cognitively robust (moderate: 1.22 [1.16-1.29], p<0.001; severe: 1.30 [1.16-1.45], p<0.001). However, physical frailty contributed to long LoS both in those with cognitive frailty (adjusted ORs for LoS>10 days, moderate frailty: 2.77 [95%CI 2.46-3.11], p<0.001; severe frailty: 6.98 [5.99-8.15], p<0.001) and without (moderate: 2.91 [2.69-3.15], p<0.001; severe: 8.31 [7.07-9.77], p<0.001). Physical frailty did not predict readmission in any group (p>0.1).

Conclusions: Physical and cognitive frailty frequently co-exist but differentially impact outcomes. Physical frailty adds little to mortality risk in cognitive frail patients, but increases hospital LoS. Findings support separate cognitive and physical frailty screening in hospital to better target interventions in high-risk groups.