Comorbidities: a key issue in patients with disorders of consciousness

The aim of this study was to identify the impact of comorbidities on outcomes of patients with vegetative state (VS) or minimally conscious state (MCS). All patients in VS or MCS consecutively admitted to two postacute care units within a 1-year period were evaluated at baseline and at 6 months through the Coma Recovery Scale-Revised Version and the Disability Rating Scale (DRS). Comorbidities were also recorded for each patient along the same period. Six-month outcomes included death, full recovery of consciousness, and functional improvement. One hundred and thirty-nine patients (88 male and 51 female; median age, 59 years) were included. Ninety-seven patients were in VS (70%) and 42 in MCS (30%). At 6 months, 33 patients were dead (24%), 39 had a full recovery of consciousness (28%), and 67 remained in VS or MCS (48%). According to DRS scores, 40% of patients (n=55) showed a functional improvement in the level of disability. One hundred and thirty patients (94%) showed at least one comorbidity. Severity of comorbidities (hazard ratio [HR]=2.8; 95% confidence interval [CI], 1.71-4.68; p<0.001) and the presence of ischemic or organic heart diseases (HR=2.6; 95% CI, 1.21-5.43; p=0.014) were the strongest predictors of death, together with increasing age (HR=1.0; 95% CI, 1.0-1.06; p=0.033). Respiratory diseases and arrhythmias without organic heart diseases were negative predictors of full recovery of consciousness (odds ratio [OR]=0.3; 95% CI, 0.12-0.7; p=0.006; OR=0.2; 95% CI, 0.07-0.43; p<0.001) and functional improvement (OR=0.4; 95% CI, 0.15-0.85, p=0.020; OR=0.2; 95% CI, 0.08-0.45; p<0.001). Our data show that comorbidities are common in these patients and some of them influence recovery of consciousness and outcomes.