The impact of psychomotor subtypes and duration of delirium on 6-month mortality in hip-fractured elderly patients.

Abstract

Studies exploring the incidence and impact of the psychomotor subtypes of postoperative delirium (POD) on the survival of hip fracture patients are few, and results are inconsistent. We sought to assess the incidence of POD subtypes and their impact, in addition to delirium duration, on 6-month mortality in older patients after hip-fracture surgery. This is a prospective study involving 571 individuals admitted to an Orthogeriatric Unit within a 5-year period with a diagnosis of hip fracture. Survival status was assessed 6months after posthip fracture surgery. Postoperative delirium was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders. Postoperative delirium subtypes were classified according to Lipowski's criteria. Cox regressions were used to evaluate the associations between POD subtypes, POD duration, and 6-month mortality, adjusting for covariates. The incidence of psychomotor POD subtypes was hypoactive 57 (10.0%), hyperactive 84 (14.7%), and mixed 79 (13.8%). Six-month mortality rates were 8.3%, 10.7%, 36.8%, and 29.1% in the no-delirium, hyperactive, hypoactive, and mixed-delirium subgroups, respectively. In adjusted models, the hypoactive subgroup (Hazard Ratio, HR=3.14, 95% Confidence Intervals, CI, 1.63-6.04) and mixed subgroup (HR=2.89, 95% CI, 1.49-5.62) showed high mortality rates and a significantly increased risk of mortality associated with POD duration as well. Hyperactive delirium was the most common POD psychomotor subtype, but hypoactive and mixed POD were associated with 6-month mortality risk. Moreover, the risk of death 6months after surgery increased for both subgroups (hypoactive and mixed) with increasing duration of POD.