Multicomponent delirium prevention: not as effective as NICE suggest?

Multicomponent delirium prevention strategies have been shown in intervention studies consistently to reduce the occurrence of delirium. Based on this convincing evidence base, the National Institute for Health and Care Excellence has advocated the widespread adoption of multicomponent delirium prevention interventions into the routine inpatient care of older people. However, despite successful reductions in incident delirium of about a third, anticipated reductions in mortality or admissions to long-term care--both clinically important endpoints statistically correlated with the occurrence of delirium--have not been conclusively observed. We hypothesise that the reasons for this disconnection are partly methodological, due to difficulties in delirium detection and blinding of study personnel to the intervention, but predominantly due to the underlying relationship between delirium and the abnormal health state of frailty; the interaction between these two geriatric syndromes is currently poorly understood.